Hi Darshan
I too agree with curio... coaching classes do help...u need to know the competion, u need to feel the competition, and also interact with them!!!
If u r already aware of the patterns of exams, the people, ur strenghts and weaknesses (VA,DI,RC,QA)...and know how too work on them, then it'll be ok that u do self-study. And yes, a regularity and determination is well needed if u wish to succeed!!!
I'll suggest, whateva path u choose, self-study or coaching, do join test-series of a good reputed coaching class. It helps a lot!!! A whole lot.
Best of Luck, for ur decision and also of the exams later in the year.
Oceanjewel