Increment After Resignation
Dear Biju, this issue can be looked at from three perspectives: labor laws (national), company policy, and good practice. Some countries' national labor laws prescribe what should happen under such circumstances, so you will need to confirm the position. Secondly, the provisions of your own company policy may dictate what should happen. If it is silent, then good practice dictates that you pay him the increment. As Archna and TS have indicated, it is a small gesture but a lifetime investment in goodwill, which modern companies cannot afford to miss.
Regards,
Njorio