Does this have to be immediate? Pakistan is a state explicitly built on religious lines and communism and Islam (or any Abrahamic religion) don't mix that well, so I fail to see how that works. The military regimes clamped down viciously on them and they never numbered more than a few thousand, never in any important positions ofpower.
India: just have Patel, not Nehru become PM in 1947, succeeded by Desai. IMO what you are most likely to get in the long run is Rajiv's foreign policy: pro-American in basic orientation, Third Way economically but triangulating (not that the word was ever used) between the US, Russia and China and never wholly lining up with one of the 3.
So something like the UAR or Nasser's Egypt? That's easier, but with the unfortunate exception of Zia all Pakistan's leaders have been secularists.
Yes, or like Syria, but point taken, nonetheless. Although, Baathists and Nasserites are secularists, technically.
Yeah, I think a theoretical Soviet-aligned Pakistan would be less full-on communism and more of a third way inspired by Arab socialism.
Pakistan wouldn't go Communist but it could go into the same sort of vague half-alignment with the USSR that India did in OTL.
Here's my best take on it. Jinnah's TB is accelerated by a few years so he dies in 1945 instead of 1948. Nehru dies in prison in 1942, so Patel becomes PM and embarks on the course I previously mentioned. Pakistan is still created, but Truman decides to give more food aid to India. Dulles dies of a heart attack in 1953, so without his rigid West v. WarPac mentality Herter or Rocky is SOS and India becomes America's primary ally in the Kush (which it always should've been IMO). The Soviets, sensing a weak civilian government in Pakistan and with their long interest in the region dating back to the Czarist era, finance the CPP and train them in Moscow. Infiltrate the military, assassinate both Khans (L.A. and Ayub) and perhaps form an alliance of convenience with the Islamists. Maybe a younger figure like EMS in India, a pragmatic but highly ideological and ruthless Communist seizes control by the late '50s and early '60s. He appeals for Soviet assistance against China and gets all the arms money and credit can buy, signs a Friendship Treaty to defer any chance of a PRC attack. So by 1965 you have a Communist Pakistan and a Western India.