Arrival to Mumbai Int'l - departure from Domestic; what to do

I am arriving end of this week to Mumbai with a plan to leave immediately without staying in town - I'll leave this for the last 2-3 days before departing from India.

I will arrive to Mumbai International. I will most likely have a flight arranged either with Deccan or Kingfisher - as soon as I make my mind up where to go - Kalkuta/Assam/Bengal or Goa/Karnataka. As far as I understand the budget airlines don't fly from International but from Domestic airport.

How much time should I calculate for this transfer? As I should lend 4.20 to Mumbay what do you reckon as the earliest reasonable time to book my next flight considering immigration, luggage, transfer, check-in and departure formalities?

Thanks Gordon

i did the same in november without an onward ticket booked, i had a bit of hassle getting them to let me on the bus transfer without the onward ticket but they did in the end. its a short bus journey & im sure that within an hour of landing in mumbai international airport I was standing at the ticket offices in mumbai domestic airport & 1/2 an hour later i was on a flight to goa...

so, id say leaving a 2 hour gap, you would be well covered but it does come down to how safe you feel about landing in mumbai on time.

thanks - what airline you flew to goa with and do you remember how much did you pay when buying just before the flight?

See also http://www.toandfromtheairport.com/mumbai.html and http://www.airportsindia.org.in/ for some general airport info, the latter is currently down (only open during business hours) or I'd give the more specific link. It's often quite detailed at least for the bigger airports.

Here go: http://www.airportsindia.org.in/mumbai/index.jsp

Doesn't look to be very good in this case. Silly.

why? becuase they don't depart from the same terminal?

No, I meant that website isn't very informative regarding this particular airport

I'm sure it was spicejet I flew with, I walked in the door, on the left there are 3 or 4 airline ticketing desks, I approached all asking about the next flights to Goa and as one was flying 1/2 an hour later, could still let me on and was the cheapest, I went for it.
I think the cost was about 35euros, cant remember what it was in INR but I was extremely happy with it.