Is it possible to set width of a jQGrid in percentage? If yes, then how?
Not directly but it is possible...
If you are wanting to set the width of the entire grid to a percentage you can use the autowidth property and it will set the grids width to the width of it's parent element (i.e. DIV) and that parent element can have it's percentage set.
autowidth: true
If you want to set the column widths by percentage you can use shrinktofit and then your column width values are basically a percentage.
shrinkToFit: true
These options and many others can be found on the JQGrid wiki