I want know about project affected reservation (both are central government project HAL and other is arm production) also any validity of this certificate?

Project Affected Person (PAP) reservation is a policy implemented by the Indian government to provide job and educational opportunities to people who have been adversely affected by land acquisition projects undertaken by the government or public sector undertakings (PSUs).

To be eligible for PAP reservation, you or your family must have demonstrably lost land due to a government or PSU project like HAL (Hindustan Aeronautics Limited) or any other related to arms production.

You need documents as proof of land ownership and acquisition by the government/PSU for the project.

The reservation might be applicable for jobs or educational opportunities near the project location depending on the specific policy of the organization or government department.

The validity of a PAP certificate can vary depending on the issuing authority and the specific job notification/educational program.
Many job notifications issued by PSUs or government departments specify the validity period for using the PAP reservation. It could be lifelong or valid for a specific number of years. Some educational institutions might have their own regulations regarding the validity of PAP certificates for reservation purposes.

I hope it helps!