Who is eligibility to appear in the Civil Service Examination?

For the Indian Administrative Service and Indian Police Service, a candidate must be a citizen of India.

For other Services, a candidate must be either

a citizen of India, or

a subject of Nepal, or

a subject of Bhutan, or

A Tibetan refugee who came over to India before the 1st January, 1962 with the intention of permanently settling in India, or

Person of Indian origin who has migrated from Pakistan, Burma (Myanmar), Sri Lanka, East African countries of Kenya, Uganda, the United Republic of Tanzania, Zambia, Malawi, Zaire and Ethiopia or Vietnam with the intention of permanently settling in India:

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.

What age limit as on 1-8-2017 has been prescribed for appearing in the Civil Service Examination for different categories of candidates? How many attempts are allowed for the same?

Unreserved OBC SC/ST P.H.
Consequential changes in number of attempts 06 09 Unlimited 09 for General/OBC Unlimited for SC/ST
Consequential changes in age limits(*) 32 years ) 35 years 37 years 12 additional years in each category (30+12 for General, 35+12 for SC/ST & 33+12 for OBC)

Whether a candidate who is allocated to one of the services participating in the Civil Service Examination can again appear in the Civil Service Examination for improvement?

except those who have been allocated to the Indian Administrative Service (IAS)/Indian Foreign Service (IFS).

Who is competent to take final decision with regard to the eligibility or otherwise of a candidate for admission to CSE?