How much kvar capacitor bank installed for 2000 kva transformer?

It depends on the power factor of the load, but for a load power factor of 0.7 on a 2000 kVA transformer the real power and reactive power are both 1400 kilo (watts and VAR). So a 1400 kVAR capacitor on the load would restore the power factor to 1, allowing 2000 kW to be drawn instead of only 1400 kW.