Hello Gowtham,

Practice can lead you to your passion. You have a lot of time to practice all the topics required in an entrance exam you want to register for in order to pursue Automobile Engineering. Start from building your basics. Read the concepts from a reliable source and then try to solve the problems. If you cannot solve at once, it's perfectly fine. Again read and try. Don't give up. Practicing mock tests and various other papers will definitely help you.

All the best.