I did not study maths in 12th. Am I eligible to get admission for CSE?

No, it comes in the category of pure science.

You want to join computer science. There is no option to come in B.tech with CSE but if you repeat 12th class then you can do B.tech. Another option is that you should take BCA (Bechlor of computer application) whic is basically firm on the computer hardware ,software and Operating system. You can