Jitendra - Your original PR broke some functionality related to display of custom fields of type File (attachments). Also didn't deal with the fact that contact_sub_type is an array for both 'main' and 'other'.
I've closed that PR and posted another which does the following:
- removes 'main_contact_subtype' AND 'other_contact_subtype' from column headers since I don't think it's useful to show only one sub-type when there might be multiples - and we're showing them in the ROWS.
- partially fixes display of contact_sub_types in $rows and preserves $rows.main/other.fileName display
- I've corrected the bad code in Merger.php which converts contact_type.name to .label (see lines 202 and 207) - but you'll need to take that approach to convert names to labels in the ARRAY of sub_types provided in $main['contact_sub_type'] and $other['contact_sub_type'].
https://github.com/civicrm/civicrm-core/pull/3652
You can review and grab as a patch to continue working on (since it's incomplete). Or merge and then continue w/ a new PR.
Other than converting names to labels, the MAIN thing left to do is to fix the actual merge of sub_types. As John noted above, it's not handling multiple subType cases at all.
PR : https://github.com/civicrm/civicrm-core/pull/3648