Hi Manikandan,
SAPIUSR should never be owner or group of any SAP directory or file, regardless of classic or new userconcept.
How many similar warnings/errors are reported?
Normally it should have no impact on the system if you change the user/group approprietely, but if you have a totally misconfigured system it might be. If you repair all warnings and errors reported by convusrcpt and the convusrcpt run(s) succeed, your system should be in a correct state.
If you have doubts please feel free to perform a complete backup, so you can restore everything, but normally the back conversion method of the convusrcpt tool should be sufficient if needed.
Best regards
Joachim