I don't think that is the GNMBT project. Arjun MK2 will be based on re-designed hull and turret of Arjun MK1 platform. Personally speaking I expect it to follow Leo-2A4 to A7 type trajectory. This project was born out of a discussion by DGMF, MOD and DRDO offcials in 2016-17, when it was decided to bifurcate the original mk2 programme into a mk1A (same basic platform as MK1) and mk2 (re-designed platform) separate programmes.
GNMBT is basically what DRDO has been clamouring to the Army since 2008-09, for replacement of their T-72 tanks, since Army had made it clear to them at that point of time that Arjun will not be ordered beyond the initial 124 no. . At that time the programme (in DRDO nomeclature) was known as FMBT project. DRDO wanted Army to frame-up PSQR based on which they will start their work. Army on their part cold-shouldered their proposal for years. Thus DRDO came up with a 50 tons Leclerc type tank design first and then a Armata type design (which is presently known GNMBT). However, the Army now has gone for SPV route for its FRCV programme and wants private players tieing up with foreign tank OEMs. It is still not clear whether GNMBT will be allowed to bid for FRCV RFI.