Dear Jinu,

In order to do BDS course you have to appear for entrance exams.

You can appear in NEET exam to take admission.

To be eligible you should have aggregate 50% marks in PCB in general category. There is relaxation of marks for reserved category as well. 

To know in detail about the NEET exam you can refer below link

https://medicine.careers360.com/exams/neet-ug

Good Luck!!