according to that maks 2021 screenshot each launcher tube can hold 12 9m96 missiles and can hold 32 9m100 missiles.
Well that is a thing too... if it holds only 32 9M100 missiles that is not four missiles per tube for 12 tubes... because four times 12 is 48 missiles... if four 9M100 missiles fit in each 9M96 launch tube then 32 9M100s should fit into 8 launch tubes.
Perhaps it is a feature of the S-350 launch vehicle that at most it can communicate and operate with 8 tubes with 32 missiles and the remaining four tubes must carry four 9M96 missiles... so it is limited to 36 missile control channels... four being 9M96 and 32 being 9M100 missiles.
Maybe it is an export system limitation.
Maybe it is an error.
They don't seem to like to talk about their new SAMs as much as I would like them to.
What we do know is that the hatches for the 9M96 missiles are huge compared with the size of the missile tubes being used.
The core problem seems to be that they might not want us to realise the extend of the number of missiles and types they can carry... they have already stated that the Redut is compatible with 400km range missiles and that suggests that S-400s should be able to be carried in the 250km and 400km range versions, as well as the 60km and 150km range 9M96 missile types as well as the 15km range 9M100 missiles.
The two real questions are... can the missiles be stacked.... a missile launcher able to carry the huge S-400 400km range missiles are going to be ten or so metres deep, which is wasteful loading much smaller lighter shorter missiles like the 9M100 types.
For each tube that could take an S-400 missile, four 9M96 missiles should fit too, but the 9M96 is not half the length of the S-400 missiles so four missiles in the tube is all you could hope for. The 9M96 missiles occupy the same diameter as a pack of four 9M100 missiles however so even without layers a missile tube able to carry S-400 missiles should also carry four 9M96 missiles and each of those 9M96 missile tubes could hold four 9M100 missiles... but the depth needed for the S-400 should allow two layers of the 9M100 missiles to be carried in that tube, so assuming layers and two layers for 9M100 missiles one Redut missile tube should be able to carry one 250km or one 400km range S-400 missile or four 150km or 60km range 9M96 missiles (in any combination... all 150s, all 60s, two of each, or three of one and one of the other), or that tube could hold combinations of 9M96 and 9M100 missiles where each 9M96 missile is replaced by 4 9M100 missiles in one layer or 8 missiles in two layers... so 1 x S-400, 4 x 9M96, 16 (one layer) 9M100 or 32 (two layers) 9M100 missiles.
This would offer flexibility and the capacity to carry enormous numbers of missiles ready to fire.
My thoughts on layers stem mainly from the fact that if you design a missile launch tube to hold the biggest longest missiles then even filling with the smallest missiles you have a lot of empty unused missile tube doing nothing.
The 9M96 are both too long to consider layers, but the much shorter 9M100 it makes sense... and is a good way of boosting numbers of missiles easily.
Look at land systems for SAMs in the Soviet Union... next generation systems normally increase the number of ready to fire missiles by a significant number each time.