Can I add new college in 2 round That is I didn't added NIT Surathkal CSE during choice filling after the result of first round can I add NIT
You can change your preferences only before locking your choices. Once you lock choices there will be no further changes in your preferences. As locking of choices is done before the starting of allocation you can not add NIT Surathkal in round 2.
However you can change your preferences after Mock Allocation Round 1 and Mock Allocation Round 2. Make sure to arrange your preferences before locking them.
Good luck.