Hello Aspirant,

See once you retain any seat in any course in NEET UG counselling of either AIQ or state quota then you become in-eligible for any of the further round of counselling. So even if you have been allotted a BDS seat and you have joined it then you will be come in-eligible for any of the further counselling based on NEET UG score and all your documents will be submitted to BDS college. You can apply for upgradation of that BDS seat but by this time most of the counselling are about to complete and in mop-up rounds there is no option for upgradation in most of the states, so you should check about this on the official website of your state's counselling authority.

I hope this information helps you.

Good Luck!!