@Marwadi Gang OFS will occur for two days ( 1st day for non retail i.e., bidding of 2L and above, 2nd day for retailers i.e., below 2L rs)
In your demat account, go to OFS Section under Corporate actions . If you don’t know where it is, in google just search how to apply for OFS in and give broker name.
There is no profit calculation. You will get shares little bit less than market price, however successful allotment is not guaranteed. It depends on the subscription figure and you can sell as usual similar to how you sell other stocks in market.
Hope this helps.