If you are using the Renderbody
in _Sistema.cshtml file, then make it as a Layout page.
And add another partial page named like MyPartial.cshtml with Layout name as _Sistema.cshtml.
Renderbody is supposed to be in the master page only. i.e., Layout page.
So your _Sistema.cshtml page should only contains the following:
@RenderBody()
@RenderSection("scripts", required: false) @*----Optional---*@
Then your your new partial page MyPartial.cshtml should contain the following:
@{
Layout = "~/_Sistema.cshtml";
}
Then use your partial page in your view as follows:
@Html.Partial("MyPartial")
Hope it helps.