If you are an NJ or Prudent sub broker then this is likely to happen. This happens when you have uploaded a transaction file twice. They do not provide a unique sequence number for each transaction which leads to the issue.
If that is not the case then see if this was manually added by you twice. Please note that you can always delete a transaction manually as well.
If duplicates are seen after uploading a feed file then please notify us immediately by clicking here. In the message body, please clearly mention the following:
investor name where you are seeing duplicate transactions
the scheme name/s