Suppose If I short Nifty 8700 Put I will receive a Premium of 958 /- per lot. Will this premium will get add to my account immediately. Can I use that Premium for day trading?
You will receive the premium to your account.Ideally you should not be using the premium received from shorting options.
As there is a potential risk in writing the options the premium received will be blocked to use it for further trade & yes it will be added in the cash margin. Once the position is squared off then the actual premium will be credited to your trading account, the same you can use to trade further. Read this blog to understand more on writing options.