I am using Amazon REDSHIIFT and want to make my table data case insensitive? How can I change my Tables data stored in REDSHIFT case insensitive?

For example: Bell, BELL, bell in a column should return all the rows when queried.
AFAIK, there's no way to do that. Redshift doesn't allow you to set specific collation settings. To get the CI behavior, you'd have to add either UPPER() or LOWER() consistently to all your queries.

Technically, you could make those case conversions during loading itself and let the application tier handle display data in the appropriate case. However, I'd recommend you do not attempt that unless you know for certain your DW will never have data sets that has to be case sensitive (i.e. source already Y has a different meaning/value from y) or an application that treats different cases differently. In those situations, you've effectively corrupted your data without knowing it.