IPs are hardcodes in applications and it would break the communication if we migrate it to the cloud. Need to extend the on-prem subnet to cloud. Can Aviatrix solve this issue?
IMHO, extending L2 to cloud is a mad-man's game. You might wanna look at IPmotion (https://docs.aviatrix.com/HowTos/ipmotion.html).
I understand it bit tricky & challenging to extend L2 into cloud. But does this Aviatrix solution works with Azure as well?
Bharat Batra yes, Aviatrix works with Azure, AWS, GCP, and OCI. This doc page has a table that shows you which Aviatrix capabilities are supported in each of the clouds: Aviatrix Overview — aviatrix_docs documentation