Hello Karthik,

GATE exam preparation is more of a continuous preparation and depends on how much time you spend on self-studying, college classes are also necessary as your first learning of engineering subjects comes from there itself. Also a good college is essential as the professors are quite supportive and knowledgeable.

I believe JNTU will be a better choice for you as it being an old college has better opportunities and an environment of study.

Good luck!!