How long does guggul take to give resin and what yield should I realistically expect?

Be realistic: guggul is a very slow medicinal shrub, and resin can only be tapped after the plant has grown for several years to a reasonable size, with meaningful collection coming later still, so this is a long term crop, not something that pays within a year or two. The resin yield per plant is small and is collected by careful tapping over the season, and because over tapping kills plants and has contributed to the species becoming endangered, sustainable methods limit how much you can take, which keeps per plant volumes modest. So total output builds slowly and depends on plant age, number of plants, soil, climate and tapping skill. Treat any yield figure as a small, uncertain range that you confirm with a research station and existing growers rather than a fixed promise, and do not expect large quantities quickly. The crop suits patient growers on dry marginal land who value the steady niche demand from the Ayurvedic trade. Verify realistic yields and proper tapping technique locally before counting on income.