is it necessary for again choice filling in 2 round neet all India quota if I had already done choice filling in round 1 neet

Also, if you wish to opt for some other college through Round 2 of counselling, you will have to mandatorily participate for second round of online counselling and choice filling, and freshly fill your college choices once again.

If you have not been allotted your preferred seat after Round 1 of Counselling, or if your allotted seat was cancelled at the time of reporting to your college, or you opted to participate in round 2 of counselling while reporting at the allotted institute after round 1, then you will be allowed to participate in round 2 of counselling. Otherwise, if you have been allotted a seat after round 1 and have joined the allotted college, you needn't register for round 2.