I have two master pages in my form,i have to get total count of current master page.
$layout.pageCount()--> total page count(including all master pages)
But i have to get the total count of current master page.
One way to count specific master pages is to use the resolveNodes menthod-
// Count all instances of master page "MP2" xfa.form.resolveNodes("#subform.#pageSet.MP2[*]").length;
If I understand you correctly then you can try the library object Master page n of m which I think does want you want:
When you place it on your Master page you get the page x of y, y=number of sheets on this masterpage.
Current page is this.rawValue = this.parent.index + 1;
Number of pages on Masterpage: this.rawValue = this.parent.all.length;