GST PAYMENT

Dear Sir/Madam

I have 3 Query

Query 1
Kindly Help me out at what % I have to make payment under QRMP

January Details
My Purchase
Cgst Amt is - 1535
Sgst Amt is - 1535

My Sales
Cgst Amt - 2358
Sgst Amt - 2358

Balance to pay 1646 of this how much percent I have to take for a payment Pls help me on this

Query 2
I unable to add details in IFF
and when I m going in payment option After clicking on Challan type on 35% the error is Coming (The CashPaid for tax Liability in last 3B is Nill so u r advised yo make make payment on self basic

Query 3
I have Failed to File IFF of Jan month so in this case should I file Jan plus Feb month both IFF in March 21

Or
Its Possible to Do same Rtn has I was doing Before Dec 20

Monthy 3 B
Quarterly R1


Pls Help me out in all my Query