Hello Biswanath, There are hardly any colleges in India that select students only on the basis if 12tth marks. Most of the colleges conduct entrance exam so that they could admit only meritorious students in their courses. No one wants poor students in their college who can't cope up with the academics. There is one college which gives admission on the basis of 12th marks:

Unitedworld School of Law takes admissions on the basis of 12th percentage. The institute provides  5 years integrated BBA LL.B program.  The institute is recognized by Bar Council of India and is affiliated to Gujarat University.