why puneet dont want pritam to be captain?

That's true,.. later the captaincy is better, as

When there remains only 5-7 housemates, immunity matters a lot,

and secondly, Pritam is strong over KAR and Renee, also all others have already been the captain, so he will be in later 1-2 weeks anyway,

and later the better , and hence need not to waste double immunity of this time - pritam who won today's task and now also as a captain !

in fact Upen also played smart

that ,...by laying down in the bedroom, among the women group and gang,..and NOT coming into the picture,... for so many weeks

he never came under the nomination,..

and this week,

either he or most likely Rene has to go !