I think the action taken by the institute against you appears to be correct.
They would be justified in terminating your services, not just suspending you.
(You have given no details of reply / justification to any of the queries)
It is apparent that you are not doing your work and the the institute has been suffering on that account. I don't see any reason why they should not be taking action against you.
It's surprising you managed to be here for 24 years.
In a private company, you would have been terminated long ago.
They would be justified in terminating your services, not just suspending you.
(You have given no details of reply / justification to any of the queries)
It is apparent that you are not doing your work and the the institute has been suffering on that account. I don't see any reason why they should not be taking action against you.
It's surprising you managed to be here for 24 years.
In a private company, you would have been terminated long ago.