Regarding denial of noc

If a government employer denies a No Objection Certificate (NOC) for applying for a job outside, the employee should first seek a written explanation for the denial, then escalate the issue to higher authorities within the organization, and potentially consider legal options like approaching the Central Administrative Tribunal (CAT) or High Court if the denial is deemed unreasonable or violates fundamental rights. 

Who has denied for NOC and did you raise the level to seek NOC ?

You have no remedy except meeting higher officers.  There is no justiciable rights.

the reasons for denial are relevant.

File writ of MANDAMUS against central government institute in high court to get noc on directions of high court .

Which Central Goverment Dept? Is it a private job that you are applying for? Please come with the facts.