Don’t worry I will let you know about UPSC Geologists' Exam Eligibility so that you can apply for it easily.

Eligibility
1) Nationality: A candidate must be either :
i. a Citizen of India, or
ii. a subject of Nepal, or
iii. a subject of Bhutan, or
iv. a Tibetan refugee

Age:
Candidate age must be between Minimum 21 years and 32 years Maximum

Eligibility
(i) Master's degree in Geology/Applied Geology or Marine Geology from a recognized university; or

(ii) Diploma of Associateship in Applied Geology of Indian School of Mines, Dhanbad; or

(iii) Master's degree in Mineral exploration from a recognized university (for posts in GSI); or

(iv) Master's degree in Hydrogeology from a recgonized university (for posts in CGWB)

Exam pattern
Part I Written Examination
Candidates competing for both categories have to appear in the following papers
(i) General English 100 Marks

(ii) Geology Paper-I 200 Marks

(iii) Geology Paper-II 200 Marks

(iv) Geology Paper-III 200 Marks

(v) Hydrogeology 200 Marks

For Category I candidates have to appear in Papers (i) to (iv) above only and for Category II in Papers (i) to (iii) and (v) above only.
Part II : Interview for Personality Test 200 Marks

Application Fees
Candidates (excepting Female/SC/ST/ PH candidates who are exempted from payment of fee) are required to pay a fee of Rs.200/- (rupees two hundred only) either by depositing the money in any Branch of SBI by cash, or by using net banking facility of SBI, State Bank of Bikaner & Jaipur/ State Bank of Hyderabad/State Bank of Mysore/ State Bank of Patiala/State Bank of Travancore or by using Visa/Master Credit/Debit Card