Drop TRACES conso files here
Select all quarters of one TAN for one financial year: 24Q, 26Q and 27Q, the .tds files.
Optional: Payment History from the e-filing portal (.csv, or paste it later in the Payments tab), last year's Q4 conso files, and the CSI file (.csi) as a challan-count check.
Everything stays on this computer. Nothing is uploaded anywhere.