I have custom list(created using VS) where I need to add a new column. But in my site collection i got the data from restoring site collection in which new column information will not be there. Now my question can i add new column to a list and restore same old site collection ?
If you still have access to the old site (perhaps in a development environment) and are using 2010, you can go into Central Admin's "Granular Backup" tool to export the desired list to a .cmp file.
When you restore a .cmp file to a list that is missing data, it will leave untouched the rows that are already part of the .cmp file and only insert the missing rows.
Now, I know your answer is in regard to columns, so, you'll have to experiment.. I only know that restoring data from a .cmp file is supposed to not touch existing rows that are already in the list. I do not know about columns.
ALTERNATIVELY: If you can restore your site collection to a development machine, add the missing column to the development instance of the list (using your .wsp, or perhaps even just using GUI tools) then create a .cmp export file of that instance.. it might then successfully restore to the production environment where you've added the same-named column via VS