that's the gunners seat, the driver sits in the hull next to the hll ammunition storage. and its only possible to move the gunners seat 300mm back if you saw off the commanders legs.
Since your model above won't be able to explain the picture above you will give the same incorrect reply a thousand times , perhaps.
the entire gunner's seat is visible along with the headrest of Tc's seat from the photo taken vertically above the crew hole.
it means the front edge of the gunner's seat is 2000mm behind the turret front gun tip according to the line drawing.
your 3d model below also shows the wrongly the gunner sitting at a place 300 mm in front of where he actually must be according to the photo of the crew hatch hole above.
B]So correct it. Don't mislead militarista to post misguided drawings based on your wrong model as he did above.
Don't misguide my close friend milarista, please.
Which means that the driver seat in the above draw must be moved 300 mm behind in the following draw to comply with that photo.
if the arjun turret was about 400-500mm taller, you might be able to position the commander in the turret bustle. but the arjun turret is flatter and wider than the leopard turret, while turret ring size is about the same.