Vistara made this announcement with photos concerning its fourth Boeing 787-9 Dreamliner registered as VT-TSP (this is likely to be the last Vistara 787):

We are ecstatic to welcome our 4th Boeing 787-9 Dreamliner™ to our fleet. This maiden flight was extra special as it became India’s first wide-body aircraft to operate on Sustainable Aviation Fuel (SAF).

Photos: Vistara.