Nil-rate exemption for ready-to-eat namkeens applies when they meet Sr. No. 29 description; otherwise specified duty applies. Goods described as ready-to-eat namkeens, bhujia and similar preparations that satisfy the descriptive criteria of Sr. No. 29 of notification No. 3/2006-CE are entitled to the nil-rate exemption even if also covered by Sr. No. 30; ready-to-eat packaged products under tariff item 2106 90 99 that do not meet Sr. No. 29's description are liable to the duty provided by Sr. No. 30.