MISTAKE IN GSTR 1

Shoeb Hasan (81 Points)

30 March 2019  
dear sir there is a mistake in gstr 1 regarding tax liability.
In august 2018 i have shown tax liability of 348845.94 in gstr 3b which is correct and paid the tax accordingly and filed the return but In Gstr 1 of that month i have wrongly put tax liability of 296245.80 rupees. so now there is a difference showing in both return. 3b was correct but gstr 1 was wrong.
what i do now
please help
thank you