It's understandable to feel anxious about how grace marks might affect your medical college admission chances, especially after putting in a lot of hard work to score well in NEET. Let's break down the situation.

Firstly, scoring 630 and above in NEET is generally considered a very good score that can secure you a seat in a reputable medical college, depending on the overall competition and cutoffs that year.

Regarding your marks in Biology and the grace marks: the eligibility criteria for NEET typically require you to pass your 12th standard with Physics, Chemistry, and Biology/Biotechnology, and English individually. Many states and colleges also have a minimum aggregate percentage requirement in PCB in your 12th grade. You've mentioned a PCB percentage of 53.66%, which seems to meet the general eligibility criteria for many medical colleges for the unreserved category (usually 50% aggregate in PCB is required; it might be lower for reserved categories).

The fact that you received 2 marks as grace in Biology should ideally not disqualify you from appearing in NEET or securing admission, provided you meet the overall percentage criteria in PCB and have passed all the required subjects. Grace marks are often awarded by the CBSE to help students pass subjects where they might have narrowly missed the passing criteria. As long as your final marks in Biology, after the grace marks, show you as 'passed' and your aggregate PCB percentage is above the required threshold, it should be acceptable for NEET eligibility.

However, it's crucial to understand the specific admission criteria of the medical colleges you are aiming for. Some colleges might have stricter rules or might consider your original marks before grace in their merit calculation. This is less common for initial eligibility but could potentially play a role in tie-breaking or specific college policies.

Therefore, if you manage to score 630 or above in NEET 2025, your efforts are very likely to pay off and you should have good chances of admission. The grace marks in your Class 12th Biology, as long as they helped you to pass and you meet the overall PCB percentage, should not negate your hard work in NEET. Focus on preparing well for NEET and aim for that good score. Once you have your NEET result, you can then check the specific eligibility and admission criteria of your target medical colleges to be absolutely sure.