Hello.
Geologist is a scientist involved in exploration and research of the history of the Earth.
To become Geologist after 10+2 you can follow the given steps :
1. You can opt in any one of the Bachelor's degree course from following courses -
B.Sc in Geology , Earth sciences or  B.Sc in environmental sciences
B.Sc (Honours) in Geology
Bachelor of Arts in Geology, Earth sciences, environmental sciences.

If you are  interested for further studies you can pursue
Masters in Science(M.Sc) in Geology and Applied Geology
M.Sc. (Hons) in Geology
Master of Technology in Geology and Applied Geology.

Hope it helps :)

Hello Aspirant,

I am no geologist to advice you on anything but definitely a Geologist in process .

You have many collages and universities that provide Geology at Graduation level and then many more Universities providing post graduation and other higher qualifications .

You will have allied subjects such as maths , physics , chemistry, statistics etc as a part of your course apart from Geology as major .

The Branch Geology has many subjects under it which are so diverse yet interconnected . As you study you will prbably grow inclined to one or many of the branches and go for your specialization.

But a short answer to your question would be, apart from the having deep theoretical knowledge and understanding of geological processes you have to be very passionate & always curious , a keen observer to become and be a Geologist.

Hope I could help :)