Hello student yes you can do BA.LLB after 12 two of the most important law entrance exams are 1)Clat and 2)Ailet eligibility criteria for clat and ailet are mentioned below
Senior Secondary School/Intermediate (10+2) or its equivalent certificate from a recognised Board with not less than 45% marks in aggregate (40% in case of SC and ST candidates).
CLAT and ailet both exams held around second or third week of May. You need to apply for both of them separately.
You can also click on the link mentioned below for more information about Clat
https://www.google.com/amp/s/law.careers360.com/articles/clat-eligibility-criteria/amp
Feel free to comment if you have any doubt
Good luck