Hey Raksha !

Since you haven't mentioned about your rank and category, I am assuming it to be of UR Category and 491 might just correspond to a AIR of 54-55k.

If we consider for AIQ, as per the stats of 2018, the closing rank was near about 17k. So, it would become quite tough for you to get in through AIQ. And since you belong to West Bengal, it would be better if you wait for the State Counselling, the performance of West Bengal students weren't upto the mark this year and this might lead to falling of Closing Rank beyond 40k. Add to that the extra 500 seats which are going to be added this year.

Even if MBBS isn't an option, you can also choose for BDS or MBBS from Pvt. Medical colleges if you wish.

Hope this helps.

Best Wishes !