Can we file RTI applications to know the procedure required to apply for patents. If yes, then to whom we have to address it?
The patents office is a public authority and the RTI Act is applicable to it.
There are multiple offices which are concerned with the aspect of patents and it would depend on the place/concerned office from which you wish to seek the information.
Under section 2(f) of RTI Act, you could obtain certified copies of the relevant documents and records.