wrong credit taken cgst and sgst instead of igst

Vijay Kumar V (Tax Practitioner) (29 Points)

10 May 2019  
In financial year 2018-2019 from April to February a client has filled his returns by taking credit of cgst and sgst in 3b.But actually he has got input only IGST.
pls suggest how to rectify the error March 3b has not filed it is pending now.