Lets do a short #T90 vs #T72 visual diff thread. #T90 is an evolution of the #T72 & was originally supposed to be called T-72U or T-72BU. Also, remember that early #T90S exported were actually #T72 turrets on #T90 hull. The pic is a T-90A Mod 1992 (feel free to correct) #εpsilon

But first, how do you know it is a #T90 or #T72 in the first place? Look at the wheels, it should have 6 road wheels with these spoke & cavity type design. If there are 6 cavities (pic 1), it is a newer #T72, if there are 8 (pic 2) older #T72. If there are 8, then confirmed #T72.

#T90M's wheel cavities (also called indentations on all #T72 and #T90) extend till the rim edge instead of just short on older #T90A, #T90S and all #T72
Pic 1: #T90M without skirts, identations till wheel rim edge
Pic 2: #T72B3, identations just short of wheel rim edge.

But what if no wheels visible. This is a #T90A, distinctions to remember.
1. Shtora dazzlers -Orange, either side of the gun
2. Commander's sight+manual RWS -Red
3. Smoke grenade launchers 2+2+2 config so 6 a side -Green
4. Laser sensors -Blue

Very easy to see distinction from side, look at the exhaust port over the 6th road wheel
1. Long: #T72 -Red
2. Short: #T90 -Green
But remember, exhaust port is only on the left/port side of the tank.

Now the most difficult distinction part 1
Pic 1: #T90A with green highlighting 3 ERA wedges no 1-2-3. They are flush and equidistant with each other so its a #T90
Pic 2: #T72 coz the red highlighted ERA wedges 1-2-3 are not flush and uneven
This arrangement is mirrored on sides

Part 2
Where the last ERA wedge ends (last ERA wedge marked by green) on the base armor, the base armor has straight lines marked in RED. This is because base armor on #T90 is welded turret plates.
On #T72 the area is smooth and curvy, marked in BLUE

Back to easy ones, if it has no wedges but bricks like below, it is not a #T90 for sure! If you can confirm other aspects then its a #T72 for sure. Now some oddballs after this.

Oddly, 2 are from #India and used by #Indianarmy
Exhibit A: #T90 commander RWS but uneven ERA wedges. These are actually early #IndianArmy #T90Bhishma which had casted turrets. They are essentially/almost #T72B3 spec.
Pic 2 shows they have the #T90 powerplant as well.

Exhibit B: Here is #India's #T72Ajeya with #T90 turret as part of fleet upgrade. CC:@Kunal_Biswas707

Just like #India, even #Russia had its fair share of early #T90A with #T72 turrets which were casted. Here
1. Shtora-Pink
2. IR sensor-Blue
3. Commander shield-Green
4: Red highlights turret curve just above turret ring, on a #T90 it is straight, its a curve here, look closely.

Showing straight turret base lines of a #T90A captured in #Ukraine marked by red in pic 1. Also, all #T90M have a smooth appearance as seen in pic 2 with a RWS panoramic sight. Pic 3 shows that #T90M has a longer turret, another distinction to keep a note of

@VinodDX9 @Kunal_Biswas707 What do you think?