If these are contracts, they're calculated separately: Aug:
Bought at 100 (Still with you)-(Has to be sold to realise profit/loss) Sep:
Shorted at +150 Rs (Has to be squared off (i.e bought) to realise profit/loss)
-200 Rs+200 Rs =0 + Expenses (brokerage+ taxes etc)
I saw the date and assumed that you bought one on 1st AUG and sold it on 1st SEP and did an intra-day trade on 1st SEP
Could you explain what you mean by end of the day profit and how did you arrived at Rs.100 profit?
Do you still have the stock you bought on 1st AUG? If yes, then you have 2 outstanding positions.