Is hsn summary mandatory

Yes, it is mandatory to give the above details.

HSN wise summary of outward supply is optional for taxpayers having annual turnover upto Rs.1.50 Cr.

It's mandatory to report HSN code at two digits level for taxpayers having annual turnover in the preceding year above Rs. 1.50 Cr but upto Rs.5.00 Cr and at four digits’ level for taxpayers having annual turnover above Rs.5.00 Cr.

UQC details to be furnished only for supply of goods.
Quantity is to be reported net of sale returns.

HSN Code is mandatory at 2 digit level to the dealer whose annual turn over exceeds 1.5 crores.