Which college should I join for B.Tech? I have only scored 56% in 12th.

You must sit for JEE-Mains as it will give you an opportunity to get a good engineering college. Else, you can look for colleges which takes admission based on 12th percentage. Check these institutes – Saveetha Engineering College, Chennai BMS College of Engineering, Bangalore Bharati Vidyapeeth De

Please visit this link. This is a college predictor by Shiksha and I hope this will help you to choose the right college- https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor&ved=2ahUKEwie-7mvrITiAhWz73MBHYuID8oQFjAAegQIAxAB&usg=AO

Hello Rishi, With this score, you can get only an average college. Try to apply for the colleges that admit students based on board exam scores. But you can work hard, and learn many things and develop your skills in the engineering field based on your interests and so, you can have a better career.