For studying BAMS you need to to qualify in the entrance exam NEET after completing intermediate with 75%. The admission into the BAMS depends on the rank you get in NEET such as you need 50% percentile for general category and 45% percentile for OBC and SC&ST 40% to get the admission.
The fee structure for BAMS may vary from 25000 to 3 lakhs per annum and it differs for different colleges.
Hope this information is helpful to you. Good luck