I've hinted at this in other posts but I'll do a quick rundown! General population is at about 10 billion, just crossing that in the last few years, but starting to stabilise with projections that things will settle down on a nice, neat ~12 billion or so.
Wealthy regions are stable at something close to replacement rates, generally meaning: Northern India, Greater Persia and MENA, Europe, Costal North and South America (but inland, particularly inland North America is still growing quite fast), Costal and Wealthy Inland Africa. Places where it's still growing tend to be, like OTL, places which are developing quite rapidly; Contraria (Australia) is most substantial here but also formerly poorer regions of Africa, particularly around the southern cone, are growing very quickly. China is all over the place as successive leaders either encourage or discourage growth and the up-and-down prosperity of the country takes its toll. Generally things are more balanced than OTL; migration occurs at similar rates but is much more thinly spread, with people moving all over to follow opportunities, passions, people, whatever, and perhaps tends to be a little more temporary than OTL with a good chunk of people eventually returning to their mother country as opportunities improve. The places really gaining from immigration are Southern Africa, South America and Contraria where lots of Europeans, Gurkhani and Persians are starting to set up shop. Central Europe is losing a lot of people as the tense situation in the Germanies isn't really good for anyone and a lot of Germans are making their way overseas. In Latin America, Parana is a real hotspot and similar to the OTL USA emphasises its "immigrant heritage", though of course there are grumbly anti-immigration sorts who want much stronger restrictions.