Hi Nikhil,
Can you pls chk OB40, FTXP settings once.
Please check in transaction FTXP--> country -->your Tax code --> in properties here have you maintained reporting cntry( ur country) correctly. please check and maintain if not.Please check GL account assignment, tax type - input/output ( these both are picking from OB40 t code) so pls chk and maintain if not. Update us in case you still face any errors.
Thanks & Regards,
Lakshmi S