[brian_]

Does Tata make an EV on the same platform? If so, either buy one to replace the Nano, or buy one that's been crashed and see how much will bolt in easy without creating many custom parts.

An electric Nano - under another brand name - was announced in 2018:
Tata Nano Electric variant gets govt subsidy – Price benefit of Rs 1.24 lakh
Tata Nano Electric aka Jayem Neo EV Spotted — The Latest Addition To The Ola Cabs Fleet
I don't know if it is really available, or if salvaged parts from wrecked ones are available, but the specs suggest what might work in the Nano.