Hereby I am mentioning the list of colleges where you can apply . The list consist of colleges providing B.Sc in Geology in Tamil Nadu : 

COLLLEGS IN TAMIL NADU 

KUMARAGURU COLLEGE OF LIBERAL ARTS AND SCIENCE , COIMBATORE 

THIRU A. GOVINDASAMY GOVERNMENT ARTS COLLEGE 

PRESIDENCY COLLEGE 

JAWAHAR SCIENCE COLLEGE 

NATIONAL COLLEGE , TRICHY 

A.D.M. COLLEGE FOR WOMEN 

THIRUVALLUVAR UNIVERSITY 

V.O. CHIDAMBARAM COLLEGE 

GOVERNMENT ARTS COLLEGE , SALEM 

GOVERNMENT ARTS COLLEGE , KARUR 

Hope it helps!

All the best for your future!