How To Show Gridview Side By Side When I Enter Value In Textbox

Gridviews can be created dynamically.

Use the Placeholder control[^] and create a placeholder on the design page.
Then add gridview controls to this placeholder on demand (based on number of entries in the text box).
E.g.

for(int i=0; i++, i<= numCount)
{
    GridView gv = new GridView();
    gv.ID = "_gridview" + i;
    placeholder1.Controls.Add(gv);
}

Set the data source of the grid views as required.