Lauraceae?: (Mixed thread): 2 correct images as above.
Local Adi in Upper Siang district of Arunachal Pradesh call this ‘combo’, an edible fruit, with a citrus-like taste. Another (possibly related) fruit is ‘harpu’. The last 4 pictures (no fruit) is the ‘harpu’. Does anyone have an ID on this maybe?

There are two different species (leaf venation is different in both).

Indeed there are two species depicted, I should have pointed that out more clearly maybe).
the non-fruiting ones seems to be Neolitsea cuipala like … suggested (thanks for that as well!) but for the fruiting one I find the nervature of the foliage (first pair from the central nerve are running almost alll the way to the tip) does not look much like that of the Litsea I see depicted (mostly the first pair reaches the margin of the leaf even before the middle section of the leaf). I hope my descriptions are somewhat clear.

I think non fruiting one appears different from images at
This seems more closer to Cinnamomum:
Fruiting one appears more closer to images at

The sterile images are of Cinnamomum while the images bearing fruits belong to Lindera neesiana (Lauraceae).

Seems correct as per images and references at

for the non-fruit bearing species I am still in doubt between Neolitsea (Neolitsea cuipala has been suggested, resemblance is very close!) and Cinnamomum. I will look further into this.
For the fruit bearing one Lindera neesiana has been suggested, but upon looking at herbarium specimen (from Kew and others) I conclude that again the nervature of the foliage is quite different, as well as the missing glaucous colouration of the abaxial side of the leaf in Lindera neesiana. Also the fruit in Kindera occurs in bunches and is much smaller than the depicted single fruit. I have no other suggestions however, the foliage makes me search towards Cinnamomum and Neolitsea as well, but the fruit again is quite different.

Any further comment with these images devoid of flowers and fruits is not possible.

I tried to check specimens in POWO and GBIF of the species listed in BSI Flora of India, but could not reach any id.

I will further check Neolitsea as mentioned in BSI Flora of India.

Such terminal perulate buds are indeed seen in Neolitsea but here the lateral primary veins of the leaves are ascending 100% way along the lamina, a feature unusual in Neolitsea except in a few rare examples in N. cuipala where these lateral primaries ascend up to 90% way along the lamina. So, the identity can be established only after seeing the flowers or fruits.