How to declare purchases in ectax new portal

Where I have to declare my Purchases in Tamilnadu Sales tax eCtax New Portal Nature of transaction Annexures /       Base Form Purchase Transactions : Registered dealer purchase within state for 1st Schedule goods 1 Registered dealer purchase return within state for 1st schedule goods 5 Registered / Un-Registered dealer Net Purchase(Purchase – Return) relating to section 12 transcations within state for First & Second schedule goods. 3…