Hi aspirant, since you have 42000 SC category rank in your JEE mains exam so based on that below are some of the colleges in which you can enroll yourself;

• Maharaja Agrasen Institute of Technology, Delhi
• NSUT, Delhi
• Sant Longowal Institute of Engineering and Technology, Sangrur
• University Institute of Engineering and Technology, Chandigarh
• Chandigarh College of Engineering and Technology, Chandigarh

Etc.

For more colleges you can also try for below mentioned link;

https://engineering.careers360.com/jee-main-college-predictor?utm_source=qna&utm_medium=jee_cp

Thank You.