Query of HSN details in GSTR 2 return

Yes HSN code is mandatory. You are telling about Draft GSTR 2 which is provided for cross references to confirm  with booked purchase 

Yes HSN code is mandatory. You are telling about Draft GSTR 2 which is provided for cross references to confirm  with booked purchase 

HSN Wise summery is mandatory in return.

How come HSN summary is possible in GSTR 2? we purchase 100 of different items in a month or only HSN summary of those whose purchase in coming in GSTR 2A we need to show ?

The format of GSTR 2 has made a provision for entering HSN codes. I advise that you should do your job by filling the HSN codes without bothering about absence of HSN codes in GSTR 1. In any case, you should advise your supplier to mention the HSN codes in future in the GSTR 1.

How come HSN code summary of GSTR 1 will reflect in GSTR 2?