Hope to add remote driving function, thank you

(it needs allow_remote_driving = true on the prototype)

thanks

Will it also reveal the map around itself like a Spidertron?

The engine doesn't support map revealing for car-type entities (such as tanks, or this mammoth tank), only spider-vehicles. You could use https://mods.factorio.com/mod/radar-equipment which uses scripting to place an invisible super-fast spidertron set to follow the vehicle containing the radar equipment :)

Alternatively, make the Mammoth Tank a spider vehicle? (Thanks for the mod recommendation though, going straight on my list)

Could do, although that has other side-effects, like pressing W to go north rather than forward, and a much more 'floaty' collision system. See https://mods.factorio.com/mod/DMV_Directional_Movement_Vehicles, which turns all regular vehicles into 'spider-vehicles'.

Yeah I wont be making the Mammoth into a spider, Radar equipment might be the best shout!

In 2.0.21 chunk_exploration_radius will be moved from SpiderVehicle Vehicle so you could have this tank reveal the map itself if you like ;)

Nice I will prob add that!