What r the dimensions of mutual inductance?

Obviously there is more than one way to do this.

VL = Ldi/dt Volts has units of Joules/Coulomb: J/C i has units of Coulombs/second: C/s

So di/di is C/s^2 L has units of J/C / C/s^2 = Js^2/C^2

Ic = CdV/dt => Ic/dV/dt = C/s / J/C-s = C/s * C-s/J = C^2/J C has units of C^2/J OR you could just type Q = CV => C = Q/V = C/J/C = C^2/J same answer

R = V/I => J/C / C/s = J-s/C^2