This is for Esperanza, who didn’t leave an email ID. I had two sources of yarn (most if not all of it non-natural fibres) in Delhi. Both of them were in South Delhi, I don’t have much idea about shops in the other areas.

1. Munirka Market, there is a store called Sushila (depot?), which sells yarn in hanks by weight, and has several different gauges of yarn. On the same row (this is the main road of Munirka) there are a couple of other stores which sell labelled skeins of yarn as well as other yarn in hanks by weight. You will have to do your own winding with these.
2. Sarojini Nagar market, in the lane where they sell vegetables (trust me, this is the best landmark) there is a line of stores amongst which is one craft store which sells yarn – again mostly by weight and unidentified. They also do needles/hooks/notions. I’m sorry, but I don’t remember the name of the store. But again, there will be several other stores selling yarn.

A couple of things to note about yarn/needles/other material in India.

In my experience, we do not get any of the following here:
1. The international brands of yarn/needles/hooks (Pony is locally made)
2. Complete content information on yarn labels
3. Larger sizes (higher than 5 mm) of needles/hooks.
4. Natural fibres, including cotton, wool, and so on.
5. Plastic hooks/needles

I might be wrong, but I haven’t encountered any of these in India.

You say you will be going to Jalandhar/Punjab. I think you might have a better source there, since I believe a lot of the yarn manufactured in India is in fact made in Punjab (Ludhiana, mostly, I think). You might have better luck finding natural fibres and larger size needles/hooks there.

I hope this will help you. *Please* write and let me know of your experiences. I’d love to build up my “database” about knitting/crochet supplies in India.