Sir I am interested in field of robotics so what should I do after 12

The learning starts like this :

Manual Robot, Semi autonomous Robot, Autonomous Robot, Humanoid robots etc.

You can start making simple Manual robotics. Practicing the controlling. Once you are comfortable may be you can then start making a Pick and place robo by using a simple mechanism.

After manual Robo, a little programming can be learnt and a Line follower robot can be designed (A line follower is a robo which automatically follows a black/white line and follows that path)

Best educational institutes :

• University of Hyderabad.
• Jadavpur University.
• Lovely Professional University , Punjab
• Birla Institute of Technology and Science
• Roorkee Engineering & management Technology Institute, Shamli

Good Luck

If you are interested to do robotics then you can opt for engineering after your 10+2.

You can check the top colleges for Robotics Engineering below

Guru Gobind Singh Indraprastha University, Delhi

SRM University, Chennai

Manipal Institute of Technology, Manipal

PSG College of Technology, Coimbatore

Sathyabama University, Chennai

Graphic Era University, Dehradun

To check the complete list you can refer below link

Top Colleges for Robotics

Good Luck!!