I'm asking because I'm reading Magnificent Delusions by Ambassador Haqqani right now, and he makes a casual reference to troops being flown into East Pakistan just prior to the 1971 war, but doesn't mention the logistics of it. Did India simply let Pakistan fly over their airspace? Did they have to go thousands of miles out of the way by flying around India? Presumably some of it would have been on ships, but what about the rest?
Two divisions of Pakistani troops (the 9th and 16th totaling 25,000 men) were simply flown into East Pakistan via civilian airliners by way of Ceylon. Their heavy equipment was shipped to them to arrive later as you presumed, and in the meantime they used equipment belonging to the oversized 14th division already in East Pakistan.
The best source I know of mentioning the specific method of moving the divisions is Anthony Mascarenhas's famous Sunday Times article "Genocide", published online in its entirety by Tarek Fatah:
Carrying only light bed rolls and battle packs (their equipment was to follow by sea), the troops were flown out to Dacca by PIA, the national airline. Its fleet of seven Boeings was taken off international and domestic routes and flew the long haul (via) Ceylon continuously for 14 days. A few Air Force transport aircraft helped.
I hope that answers your question!