To authorise legal heirs of a flat in co op hsg society how and from where to obtain letters of administration ? Procedure, supporting documents required and estimated time as well as money required?

Procedure, File a petition in the probate court

supporting documents required acceptance of letters
Petition to probate will or for probate of intestate estate

estimated time as well as money required?
Why? We aren't allowed to bid the job here.

There will be a filing fee depending on where it is.