Looking at the ToE, it seems this "Brigade Combat Team" more to be like our Armd Bde Gps, like 8th at Mangla, rather than a standard armored Brigade.
8 IAB originally has 2 armor regiments and 1 mech infantry battalion.artillery regiment. signal company.
Thats 90 MBT. 50 APC. 18 Arty Guns.
Corps HQ attaches more units to it.
1 Armor Recce regiment from Corps reserve.
1 AD regiment from Corps AD Bde.
1 Engineers company from Corps Engr Bde
1 HAT regiment or maybe 1-2 company's
1 LAT regiment or maybe 1-2 company's
1 more infantry Battalion, mechanised or motorised from Corps Indp Inf Bde or from any Div under Corps HQ.
Now 8 IAB has swelled up and becomes 8 IAB-Group and has all the above units under its command, some of which are part of Corps HQ basically.
Thats 120+ tanks. 100+ APC/tracked ATGM carriers.8-12 ATGM jeeps.18 Arty Guns. 18 SAM systems.
8 IABG had 3 armour regiments and various other units attached to it, during 1971.
Incidentally don't our Armoured Regiments all now have an ATGM Sqd attached as well?
Every Armour regiment had few RR guns which are probably replaced with ATGM now.