Chaas / buttermilk (salted, thin)

One serving of Chaas / buttermilk (salted, thin) — 1 glass (240 ml) — comes to 47 kcal, 3.4 g protein, 4.6 g carbs and 1.7 g fat. Scaled to 100 g it works out to 20 kcal and 1.4 g protein, which makes it not a meaningful protein source on its own for a dairy item. That single serving is about 3.1% of a 1,500 kcal day and 2.4% of a 2,000 kcal day, so it's more of a filler than a target-hitter on protein without much extra planning.

Walking off Chaas / buttermilk (salted, thin) takes roughly 1,175 steps, using the rough approximation of 0.04 kcal burned per step (a population-average estimate for a moderate walking pace, not a personalised number). At ₹5 a serving it costs about ₹29.4 for every 20 g of protein it delivers, which is a mid-to-high price for protein compared with dal, eggs or soya chunks. It fits nearly every Indian diet type, including vegetarian, Jain, eggetarian. It works at lunch and the evening snack slot. It's commonly eaten on fasting days (Navratri/Ekadashi-style).

If you want variety without changing the macros much, the closest swaps in the dairy category are Butter, Processed cheese slice, Curd / dahi (toned milk), Curd, home-set from full cream milk — each keeps a similar role on the plate while shifting the exact protein-to-carb balance a little.