You mentioned analytical requirements for (1) food and (2) water.
(2 )i assume you mean drinking, eg bottled, water quality. From memory there is an Indian Standard for this as is usual in most countries.
many (prob.most) local Standards are based on one or more of a handful of International Standards, for example, as already noted, WHO. Many of the latter have been posted on this forum. Of course if you intend to export, the destination requirements will also come into play.
(1) The answer really depends on what categories of foods you plan to manufacture.Perhaps you could expand a little. The generic answer to yr query is that the analysis details will typically be focussed on determining compliance to the product specification.