Dear Shyamprasad Rao, though you have raised a query, you have not mentioned in what capacity you work in the Govt Corporation. Are you an officer or a lower cadre employee?
Personal Work During Office Hours
Employees in general, whether from government services, semi-government services, or private organizations, do some amount of personal work during office hours. Therefore, as a corollary, if they do some work during their leave, then there is nothing wrong per se.
Approvals and Official Decisions
Nevertheless, government employees sign certificates or other important documents in the course of their work. These approvals or their official decisions should not create a problem for them. If an inquiry were to take place, the question could be raised as to why the government employee had given some approvals despite being on leave.
Recommendation for Approval
In government services, everything happens with the approval from a "competent authority." Therefore, I recommend you obtain approval for the work you will be required to do while on leave. This approval will provide protection in case of any unforeseen circumstances.
Thanks,
Dinesh Divekar