AMU BA LLB is a university level entrance (Aligarh-100 seats, Malappuram-60 seats and Murshidabad-60 seats) for five-year integrated law programme whereas CLAT is a national level entrance for 19 NLUs conducted for 2400 for undergraduate programmes and 624 for postgraduate programmes (approx.) seats.

To know more about the same in detail, you can go through the below links -

https://law.careers360.com/articles/amu-ba-llb

https://law.careers360.com/articles/clat

Good Luck!!!