What is the loss if i write 5 lots of nifty at 10 rs premium and on expiry it increases to 15, did i loose my whole capital with which i write 5 lots?

General
2

No ur loss will b 5 lots (125)*loss(5)=625 … this is if u cover ur short position on options before expiry if u let it lapse then ur loss will b increased with higher STT

3

@mandar,
Please check about the higher STT thing.
Also the loss if let it expire will be based on strike price and closing price, not on option premiums.
If he has sold nifty option call 8600 and nifty closes at 8612, then his net loss would be 8612 -8600 = 12 rupees minus the inital payment he received by shorting i.e. 10 rupees.
So net loss would be 2 rupees.
He need not pay STT during expiry, STT is already paid while writing the option.

4

Correct Astroguru
The reason is that the Qn is silent as to details of kind of options (call or put) and also the strike price.