Wilful tax evasion under Section 276C includes false entries, omitted records, under-reporting, and amount-based punishment bands. Wilful attempt to evade tax, penalty or interest under Section 276C includes false books, false entries, wilful omission of entries, and other circumstances enabling evasion. The provision also covers wilful attempts to evade payment and intentional under-reporting of income, with civil penalty proceedings and criminal prosecution capable of proceeding simultaneously. The text outlines amount-based punishment bands, including imprisonment and fine for higher and intermediate thresholds, and fine-only treatment for lower amounts, while also noting an earlier regime with minimum and maximum imprisonment ranges.