
Yes Ajay it is possible. Above code will insert it in head tag. However if you want to put it before body tag. than following code snippet will work for you.
string jsScript = "<script type=\"text/javascript\" language=\"Javascript\" src=\"yourscriptFile.js\">";
jsScript += "</script>";
Page.ClientScript.RegisterStartupScript(this.GetType(), "Key", myScript, true);
Thanks and Regards,
Swapnil