LLB can be done in two ways !!
- an integrated 5 year course (bba llb , bcom llb)
- another after when you are done with your graduation - 3 year course
The better is you should do it after 12th so that it can save your 1 year .But it requires hardwork to prepare for CLAT entrances.
If you want to pursue after 12th ...you have various universities to get in , for which you have to appear for CLAT Or LSAT( law school admission test ) .
Forms for CLAT are out ...to know more about it you can refer to the following link