If I buy stock on futures paying full margin will I be charged with interest
No, as long as you hold the exchange prescribed margin(SPAN+Exposure), the broker will not charge you any interest.
Say your position took a loss, the position will be marked to market and your account balance could become negative, in which case, you might be charged an interest by the broker along with an exchange penalty.
If you are starting of with F&O trading, you should read Varsity first
thanks man .and i have another one . i couldnt find option withstike price near to spot price in kite .why? for example tcs 1780 is the max i can find.now it trades in 19 hundred something