Suppose you receive a repair service of Rs. 10000 from Mr. A which is excluding GST of 18% (9% CGST + 9% SGST)
Now, you will first book the service of Mr. A in Journal Voucher as below. Dr. Repair & Maintainance Cr. Mr. A
Now you will pay Mr. A Rs. 10000 and pass entry in Payment Voucher as below Dr. Mr. A Cr. Bank/Cash
Now, as it your liability to pay GST under RCM, you will need to increase your GST liability as below. In Journal Voucher press Alt+J Type of duty/tax - GST Nature of Adjustment - Increase of Tax Liability Additional details - Purchase under Reverse Charge
Dr. Reverse Charge Tax ( Current Assets) 1800 Cr. CGST 900 Cr. SGST 900
Now pay your both taxes and pass entry as below In Payment Voucher press Alt+S Tax Type - GST Payment Type - Receipant Liability Dr. CGST 900 Dr. SGST 900 Cr. Bank/Cash