He was a smallish gent, and presumably, would have carried a weapon more as a ceremonial totem or as a means of setting an example to his followers had he thought that was the best and most pragmatic course for them to follow at the time, as a means of quickly and clearly demonstrating to them that *it's time....* He might well not even have bothered to load or testfire such a symbolic personal arm, but yet it would have served him. And he would have been in and out of vehicles, possibly even aircraft, as he travelled, so would look for something reasonably compact and convenient, if not necessarily concealable. I don't expect an overly great concern for his own life was an overriding consideration for him, but as a good leader, I'd not be surprised if he'd at least attempt to set a personal example or teach a lesson to be followed by his conduct and deeds.
My guess, of the arms available in his time? A Stirling/Patchet SMG, L2A3 or variant thereof, fairly common in that part of the world, more convenient than most rifles, and a bit less crude than a Sten gun. They're simple, compact, have low recoil and low noise, and are quite suitable for use in cities or at night, if no substitute for a good rifle, but make for a pretty fair militia, police or home guard defense weapon. There are still quite a few in service, mostly in police hands, in India, Pakistan and Nepal, and they'll likely be heard well into the first half of this century just as they were in the last half of the latter one. Of today's choices, that Tavor shorty version would be an approximate equivalent, and it too would serve such a role quite well.
"Among the many misdeeds of British rule in India, history will look upon the act of depriving a whole nation of arms as the blackest."
-- Mahatma Ghandi
