Regarding debit, credit note

Raise the Debit note as if you want to issue Invoice, you cannot increase the quantity.

As per section 34  of the CGST 2017  only supplier can  issue credit note / Debit note  for specific  reasons mentioned in section 34.

yes mr prasad is correct ...

Actually the format of return  filing in GST as per section 39 cgst is that first to upload the gstr 1 then after gstr 2 & lastly the gstr 3 . so once the gstr1 is uploaded all the credit/debit notes issued by supplier will be reflected in 2a of recepient & from there he can accept & reject the same. hence the recepient is not required to upload any debit/credit note , but this does'nt mean that recepient cannot raise the debit/credit note, he can ...  yes.... in case if supplier missed to upload the same in that condition the recepient can upload debit/credit note which will be reflected in 1a of supplier & the same can be accepted by  supplier