The following advise from personal experience of being over there this year……
It’s the MOHA clearance that can take ages. Around 8 weeks in cases. Getting the visa is not so bad. Make an appointment and turn up. Don’t, though, go to Edinburgh or Birmingham to get the visa. Edinburgh, off their own back, decided to issue guys with an "employment" visa. This will not get you offshore, but only get you sent back to Mumbai or UK to get the correct "business" visa. Birmingham only issued 100 visas a day. If you were number 101 in the line….come back tomorrow sonny!
Also, only London issues a 12 month visa. You need the MOHA to get a visa. However, the MOHA needs to be renewed every 6 months. Even though you may have a 12 month visa! That’s India for ya!!
Obviously check that the above is still valid, but that’s how it was for me & the guys I was with.
If you go to London and need to stay over, the Embassy is right across the road from the end of Drury Lane. At the other end of Drury Lane is a Travelodge. 5 mins walk from the Embassy. Half way down Drury Lane is a decent irish bar for a couple of beers and food.
As for the hanging around at port immigration………charge up your ipod and take plenty water………Enjoy India….. 😆