What id “H”​ i.e. enthalpy for an isochoric process. Is it different for reversible and irreversible?

Enthalpy is an estimation of vitality in a thermodynamic framework. It is the thermodynamic amount proportionate to the aggregate warmth substance of a framework. 

For procedures under steady weight (Isochoric) , ΔH is equivalent to the adjustment in the inside vitality of the framework, in addition to the weight volume work that the framework has done on its environment. This implies the adjustment in enthalpy under such conditions is the warmth assimilated (or discharged) by the material through a compound response or by outer warmth exchange. 

YES enthalpy continues as before.