Notice Period

Tenancy Types and Management

I have a tenant who moved into a property in February using an RLA AST Tenancy.
He is now late on his rent and states he may need to serve notice claiming his accounts have been frozen by Police and HMRC - His credit checks and references (from his boss) came back fine and although I appreciate his honesty I need to make sure that I proceed properly.

Can a tenant give notice in the first 6 months?

If he leaves, and if an alternative tenant can not be found, is he still liable for council tax etc for the remaining term?

Normally a bond is used to ensure against damage, if the tenant doesn't pay rent and tries to claim his bond can be used, how do I protect against damage? (Not only this he is almost a week late and has not yet provided notice so there is still the rent owning in addition to the month - until such time as he does)

Is there a specific form I can download if using the tenants bond (at his approval) is an end resolution (assuming no damage has been caused)

Kind Regards