S. 251 : Appeal-Commissioner (Appeals)-Powers-Assessment-Ex parte order-Officer issuing notices should strictly explore possibilities of sending notices through some other mode as prescribed in section 169(1) of GST Act which were also valid mode of service under Act-Delay of six months-Application for condonation of delay was rejected-On writ the delay was condoned, subject to payment of Rs.5000 to the credit of the Principal Government of Naturopathy College and Hospital-Matter remanded to the file of CIT(A) to decide on merits. [S. 143(3), 246A, Central Goods and Services Tax Act, 2017, S.169(1), Art. 226]