For admission in B.A.LLB, one has to take CLAT. It is an entrance exam for admission in many law colleges that offer BALLB program. All NLUs take CLAT score for admission. NLU Delhi on the other hand takes AILET score for admission.Other than that You can also appear for BHU-UET, Symbiosis Entrance Test. AMU law entrance exam, BVP CET Law, AIL Entrance test, LSAT, CU LLB, MH CET  to name a few. Fees of all the colleges varies. For that instance you can check their official websites to get a rough figure.