greetings pravesh,

For studying mechanical engineering, there is no as such minimum eligibily criteria for entrance in B.tech courses but you must pass you 10th class.

you need to opt for PCM in 11th class for studying engineering.

since you are an engineering aspirant, i would advice you to study science(physics, chemistry) and mathematics in full swing. make sure you clear your basic concepts of science right in you 10th standard.

mechanical engineering is basically the in depth study of machines and their functions. ou may even explore other branches in engineering like Computer science, electronics, civil, chemical, automobile, aeronautics, IT, electrical etc.

also, you may even join a coaching institute in class 11 for the JEE preparations like fiitjee, VMC, akaash, pace, resonance, allen etc.

try to get in the top colleges like iits, nits, iiits etc.

good luck!