purchase details in gstr 4

no only if purchase under reverse charge need to fill in returns

not need to give any puchase /sales details in gstr 4

if you have Purchase under RCM like GTA service then you have to give info in 4B ( B2B ) for registered
if you have unregistered purchase then have to fill details on 4c and pay RCM on it

keep in mind if you have to file for july - sep then you have to pay RCM on 4c
if you have to file oct-dec then if you haave purchase till 12 oct on it you have to pay RCM ... on GTA you have to pay RCM compulsary

4B and 4C the column who raise your tax laibility so please be carefull to fill these details
after uploading your json check your preview first then submit
after submit no chance to edit

okay thankyou.