Hi Swikriti
It is difficult to get a college in 15% All India Quota but u can try for private seats in your state . Some of the dental private colleges in Bihar are :

• Buddha Institute of Dental Sciences and Hospital, Patna
• Mithila Minority Dental College and Hospital, Darbhanga
• Sarjug Dental College and Hospital, Laheriasarai
• Dr SM Naqui Imam Dental College and Hospital, Darbhanga

You can also try for homeopathic, ayurveda and physiotherapy courses as they also have a lot of scope. The list of colleges for these courses in your state are given below:
https://medicine.careers360.com/colleges/list-of-medicine-colleges-in-India?f%5B0%5D=sm_college_degree%3AB.A.M.S.&f%5B1%5D=sm_college_degree%3AB.H.M.S&f%5B2%5D=sm_college_degree%3AB.P.T.&f%5B3%5D=im_field_ownership%3A967&f%5B4%5D=sm_college_state%3ABihar
You can also predict the colleges u can get with the help of the college predictor by filling in the required details in the link given below:
https://medicine.careers360.com/neet-college-predictor
Best Wishes
Era Madaria