Whether or not he will be able to be there for the submission of the visa application will depend largely on both how long he intends to stay there for and how long it takes to get the NSO copy of the marriage certificate. It has been known to take months for this to come through and by then all of the other stuff he has brought with him, wage slips etc, will probably be quite a bit out of date.
It would probably be best for you to advise him to treat the process of getting married and the process of applying for a visa as 2 completely separate issues. If he takes the stuff with him that is required and gets married, then once the NSO marriage certificate comes through they can start looking at the visa process. Maybe you should also advise him that it is worth taking a bit of time over the visa application, what is included with it and how well it is all put together as this can make a big difference to the outcome.
Iain.