Can I book my loss at any moment irrespective of strike price before expiry

Hi Friends,
I have bought call option of TataSteel May 330 @prem val 7.
Now its around 300 @prem val 2.

I can see LOSS here.

I am new to options trading so like to know some details.

My query is, Can I book my loss at any moment irrespective of strike price. Or I have to wait till expiry date to exercise my position.

Also, If I will square off @Prem val of 2, then my loss will be:
(7-2)*1000= Rs. 5000. loss
where, 1000 is lot size.

Please advise, am I correct in this calculation.