Every year, Opfin validates the tax declaration of all employees. This is usually done in the month of January. Before the validation exercise starts, we will usually send 2-3 emails to all employees to let them know about it so that all the proofs of those declarations can be uploaded.
If you have received an email from Opfin stating that your declaration has been removed or altered, then that will be because either you have not uploaded any proofs, or the proofs were of a different amount compared to your declaration. Do note that any such alteration will usually affect your TDS and thus your in-hand salary in future payrolls.
Even after receiving this email, you can still update your tax declaration by going to the Tax Deductions page in Opfin. However, any update that you make now will have to be approved by your organization's Opfin administrators. Please do not contact Opfin support for these approvals, since we only validate the proofs once.