How to fix the position of a scroll bar....after selecting a row in grid view in an asp.net page

you have to use in web.config in in your aspx file

the maintainScrollPositionOnPostBack=true

<system.web>
  <pages maintainScrollPositionOnPostBack="true" validateRequest="false /">

usually with that attribute the page mantain the scoll position during postbacks.

if you have problems in that you can look that reference : Maintain Scroll Position in Panel, Div[^]

OR

(a bit tricky) you can save the scroll position on click into a cookie
and at page load (postback) you read the position from the cookie

in my application i have rad ajax manager and
i use that code to save and retrieve scroll position from cookies
the cookies fuction are available here [^]

but my needs are quite differents than your try the solutions above before