The customer care number of Snapdeal is 09212692126. Please note this is customer care number so it is most probably for buyers. Are you asking this question as a buyer or seller? If you are a buyer go right ahead and use this number. It may not be of help to sellers since all their queries may be handled by another department. Anyway, sellers are provided with contact numbers of persons to contact on Snapdeal so a seller would not ask this question. I assume you are a buyer.
Frankly, if you are a seller and are asking this question, I find it a bit surprising. Surely, during the exchange of emails with Snapdeal during the registration process and afterward, you will have noticed the numbers they have provided for you to call in case of the query? Download their seller app and they will have a button you can tap to call them.
What use is phone number? It goes usually into IVR. You get fed up. Better send email to email@example.com or use any of their social media buttons to leave a comment. Go to sellers.snapdeal.com and there is a live chat option. Best to use that option if you are a seller and this will ensure your query goes to the right person.