Hello Stock 72,
I not understand why you try to know the nifty level at expiery. You are not has any set up which has payment amount and know of risk amount if postion keep till expiery. You are trade only buy option of different strike price. Sometime you buy out money option and keep and try your luck if your thinking is right. I am 100% sure this not the way to trading in option. and specally for keeping till expiery time. No.
If you are gambling with only direction position of buy option so you should has a 1/2/3 day idea of nifty and not the expeiry day level. You has to change the strike price of your direction position every 1/2 day becase there is time decay and volatity efact in option. So it is not a simple thing like share trading. You has to get many thing corract and has keep change the strike price, quanlity, etc.
What you are do is gambling. I think like this you will the there only, make and loss and loss and make money.
Thank you and best of luck.