For the Civil Services Examination, UPSC lists some criterias which tell us whether a candidate is eligible for this exam or not. Below are the details as mentioned in the notification released by UPSC-
(i) Nationality
(1) For the Indian Administrative Service and the Indian Police Service, a
candidate must be a citizen of India.
(2) For other services, a candidate must be either:—
(a) a citizen of India, or
(b) a subject of Nepal, or
(c) a subject of Bhutan, or
(d) a Tibetan refugee who came over to India before 1st January, 1962 with the intention of permanently settling in India, or
(e) a person of Indian origin who has migrated from Pakistan, Burma, Sri Lanka, East African countries of Kenya, Uganda, the United Republic of Tanzania, Zambia, Malawi, Zaire, Ethiopia and Vietnam with the intention of permanently settling in India.
Provided that a candidate belonging to categories (b), (c), (d) and (e) shall be a person in whose favour a certificate of eligibility has been issued by the Government of India.
Provided further that candidates belonging to categories (b), (c) and (d) above will not be eligible for appointment to the Indian Foreign Service. A candidate in whose case a certificate of eligibility is necessary, may be admitted to the examination but the offer of appointment may be given only after the necessary eligibility certificate has been issued to him/her by the Government of India.
(ii) Age Limits
(a) A candidate must have attained the age of 21 years and must not have attained the age of 32 years on the 1st of August, (concerned year) . Necessary action to make corresponding changes in respective Rules/Regulations pertaining to various services is being taken separately.
(b) The upper age-limit prescribed above will be relaxable:
(i) up to a maximum of five years if a candidate belongs to a Scheduled
Caste or a Scheduled Tribe;
(ii) up to a maximum of three years in the case of candidates belonging to
Other Backward Classes who are eligible to avail of reservation
applicable to such candidates;
(iii) up to a maximum of five years if a candidate had ordinarily been
domiciled in the State of Jammu and Kashmir during the period from
the 1st January, 1980 to the 31st day of December, 1989;
(iv) up to a maximum of three years in the case of Defence Services
Personnel, disabled in operations during hostilities with any foreign
country or in a disturbed area and released as a consequence thereof;
(v) up to a maximum of five years in the case of ex-servicemen including
Commissioned Officers and ECOs/SSCOs who have rendered at least
five years Military Service as on 1st August (concerned year) and have been released;
(vi) up to a maximum of five years in the case of ECOs/SSCOs who have
completed an initial period of assignment of five years of Military Service
as on 1st August, (concerned year) and whose assignment has been extended
beyond five years and in whose case the Ministry of Defence issues a
certificate that they can apply for civil employment and that they will be
released on three months’ notice on selection from the date of receipt of
offer of appointment.
(vii) up to a maximum of 10 years in the case of blind, Hearing Impaired
and Orthopaedically handicapped persons.
(iii) Minimum Educational Qualifications : The candidate must hold a degree of any of Universities incorporated by an Act of the Central or State Legislature in India or other educational institutions established by an Act of Parliament or declared to be deemed as a University Under Section-3 of the University Grants Commission Act, 1956, or possess an equivalent qualification.
(iv) Number of attempts:
(a) Every candidate appearing at the examination who is otherwise eligible, shall
be permitted six attempts at the examination. Provided that this restriction on
the number of attempts will not apply in the case of Scheduled Castes and
Scheduled Tribes candidates who are otherwise eligible.
(b) Provided further that the number of attempts permissible to candidates
belonging to Other Backward Classes, who are otherwise eligible shall be
nine. The relaxation will be available to the candidates who are eligible to avail
of reservation applicable to such candidates.
(c) Provided further that a physically handicapped will get as many attempts as
are available to other non-physically handicapped candidates of his or her
community, subject to the condition that a physically handicapped candidate
belonging to the General Category shall be eligible for nine attempts.
Necessary action to make Corresponding Changes in respective
Rules/Regulations Pertaining to various services is being taken separately.
(d) The relaxation will be available to the physically handicapped candidates who
are eligible to avail of reservation applicable to such candidates.
Note: (i) An attempt at a Preliminary Examination shall be deemed to be an
attempt at the Civil Services Examination.
(ii) If a candidate actually appears in any one paper in the Preliminary
Examination, he/she shall be deemed to have made an attempt at the
Examination.
(iii) Notwithstanding the disqualification/ cancellation of candidature, the fact
of appearance of the candidate at the examination will count as an
attempt.
(v) Restrictions on applying for the examination: A candidate who is appointed to the Indian Administrative Service or the Indian Foreign Service on the results of an earlier examination and continues to be a member of that service will not be eligible to compete at this examination.
For Example- In case such a candidate is appointed to the IAS/IFS after the Preliminary Examination of Civil Services Examination, 2017 is over and he/she continues to be a member of that service, he/she shall not be eligible to appear in the Civil Services (Main) Examination, 2017 notwithstanding his/her having qualified in the Preliminary Examination, 2017.
Also provided that if such a candidate is appointed to IAS/IFS after the commencement of the Civil Services (Main) Examination, 2017 but before the result thereof and continues to be a member of that service, he/she shall not be considered for appointment to any service/post on the basis of the result of this examination viz. Civil Services Examination, 2017.
(vi) Physical Standards: Candidates must be physically fit according to physical standards for admission to Civil Services Examination as per guidelines given in Appendix-III of Rules for Examination published in the Gazette of India.