GST ITC 2A and 3B

Hi, 

My Vendor filed the GSTR1 and it has been reflected in my GSTR2A, can I release the payment to him??

I read some article on google that, it is also important to file the GSTR3B, in this regard how can I know that update whether he filed the GSTR3B or not

if it's possible! tell me how

I'm paying the vendor payments if their bill reflects in Portal, It is the right practice or??

Please suggest!!