20 coach VB with 1330 seating capacity is difficult to fill even in NGP Mumbai route. 832km will take 11-12hrs, even Amaravati to Mumbai takes 9-10hrs how many will waste full day and travel. Even in successful VB routes the travellers are not travelling for long hours. For Mumbai Ahmedabad 5 hrs journey for 1000 seats 400 are from Mumbai to Surat another 600 are Mumbai to Vadodara AHMD with WL 100 means each sector can accommodate 200 more travellers and 20 coach can fill the seats.
Replace the rake with 8 coach
Option...
more... 1 Nagpur SC Dep 600 SC 1300/1510 NGP 2210 triweekly
Option2 Nagpur 600 Nasik 1400/1500 Nagpur 2300 triweekly RSA with single rake.
For Nagpur Mumbai Bhusaval is half section and an intercity with 20 coach with 7hrs Run time in each section will be successful as each each section will be covered in one half of the day and not many options for intercity travel during day. It's surprising that the 2 sectors doesn't have intercity trains.