[quote=@Durandal]
<Snipped quote by Willy Vereb>

It is a fairly large gun, when I said two people operate it I meant that's the only thing they carry. But yes, they use anti-tank warheads. Faster than missiles.
[/quote]Problem with electronic weapons that they are even more cumbersome than conventional weapons.
Unless you go under certain limits.
Granted, you probably don't need the gun for more than a few shots so perhaps putting together several or dozens of regular "railgun rifle batteries" is enough to power the system.
The barrel would still require to be crazy-long and overall we talk about tons of weight here to make an "anti-tank railgun".
Then there's the much-obvious issue with the recoil. You'd need a large and rather stable platform for any level of safety and reliability during fire.
If you want an actual anti-tank railgun you need a tank, a comparable vehicle or something like a towed field artillery.
That's why I didn't recommend this to you.

Having something more similar to an altered coilgun mortar could be more viable.
Basically think of a coilgun but it launches a warhead at higher velocities. Somewhere around the supersonic range, for example.
This of course renders your system into an actual cannon with the recoil to deal with which explains why the weapon is heavy and needs two men to operate.
Personally I'd still prefer missiles for their softer launch and guided nature but it's really just a matter of opinion.