Can Security Personnel be members of Union and participate in the Election process as Candidates too?

As per Statute, can the Security guards working under a Contractor in Karnataka be exempted from.forming Unions or becoming member of any Trade union and participating in the Election process as Candidates too? If any Clauses of Law prevents it , or Court Orders prevents it or permits it, the same may kindly be shared

I do not think anyone can be forced to join a union.
But at the same time, you can not prevent him either.

Unions are banned only for the armed forces and police