I heartily Thank You Maya Kirova.

But it is shoing something like " N/Nan/0Nan" 

but I somehow managed to bring the desired output by setting the value through

$(".selector").igEditor("value", new Date(value.TentFrmDt));

where :

IN Model

public string TentFrmDt { get; set; } and

 public Nullable<System.DateTime> TentativeFromDateDt { get; set; }

and

IN Controller

 TentFrmDt=String.Format("{0:d}", TentativeFromDateDt);