Regarding the composition of the Il-76 regiments, it seems that this changed sometime after the appearance of the 235th VTAP regiment, which was initially equipped with a squadron of 9 Il-76MD at its inauguration.
The classic composition of the Il.76-MD regiment had been 27 aircraft in 3 squadrons of 9
After 2009, it was reduced to 2 squadrons of 9, with a separate detachment of another 4 Il-76MD from the 224th LO, each 4 regiments (Pskov, Tver, Orenburg and Taganrog)
In fact, at the Ulyanovsk base a parking lot was prepared for the first squad with 9 marks, while further north a parking lot for another squad of similar capacity began to be built.
Between the end of 2019 and 2020, 12 older Il-76M aircraft were put into operation, which were in reserve, which went to Ivanovo, apparently for the 610ºTsBPiPLS
However, the 81st VTAP was later restored.
The aircraft movement suggests that the composition of the regiment varies from 9 + 9 + 4 of the previous years to a standard composition of 12x2, which in some cases includes commercially licensed aircraft of the 224th LO mixed within squadrons
The variation in the number of aircraft in the contracts also suggests the change in the number of aircraft in the regiment's composition.
At first, 1+39 Il-76MD-90A and 41 Il-76MD-M were hired, enough to renew the 4 existing regiments : 2 regiments x18 + 4 for training (plus one prototype in the case of Il-76MD-M).
Later the contract of the Il-76MD-90A was changed and the total number is 28 (1 + 13 + 14), which gives for a regiment of 24 plus 4 for training.
As for the Il-76MD-M, it provides for 3 squadrons of 12 and 4 for training, therefore in a squadron of 12 Il-76M will temporarily complete one of the regiments in a mixed way.
It seems that squadrons of 12 aircraft is going to be standardized, both in fighters, bombers and transport aircraft.
http://aviapressphoto.com/11517/The first flights of the revived air regiment
JANUARY 15, 2021
On December 1, 2020, at the Ivanovo-Severny airfield, the 81st military transport aviation regiment was revived, which became part of the 12th military transport aviation division of the BTA
According to this publication, the squadron of 12 Il-76Ms repaired just before 2020, was assigned the 81st VTAP and not for the 610th TSBPiPLS, which until then had several Il-76MDs, and a pair of Il-76MD-90As.
Then the composition of the 81st VTAP would be 1ºAE: Il-76M, 2ºAE: Il-76MD-M (in process), 3rd AE: An-2T
The reason for activating a squad of Il-76Ms is that there are no more Il-76MDs available for this expansion of the VTA structure.
Actually looking at the satellite photos of the Ivanovo base it is difficult to distinguish just by the size the Il-76M from the Il-76MD, I would say that the main difference is the ailerons apparently much larger than the Il-76MD
Apart from these 12 Il-76M, there were only 3 others in operation in Sescha, but now it seems they are in Tver
Maybe some will be parked in reserve somewhere
Then there will be in the medium term:
1 regiment with Il-76MD-90A
1 regiment with Il-76MD-M
1 regiment with 1 squadron of Il-76MD-M and another of Il-76M
3 remaining regiments will follow with Il-76MD, although surely the first Il-78M-90A dual-use transport / tanker will be put in one of these regiments, probably Orenburg or Tver
the number of soviet Il-76 known available are 137 (122 Il-76MD and 15 Il-76M), just for 5 regiments of 24, and some for training and other units (Half a dozen in Chkalovsky and 3 in Sescha)
the 6th regiment with the new Il-76;D-90A, for the moment 8 received, included 2 for 610º TsBP