Yes, 'some of' always needs to be followed by an article or other determiner e.g. some of the time, some of the people, some of the money, some of the goods. However, in this case it would be better use just 'some' rather than 'some of the' i.e.: 'some small-scale marketplaces'. I presume you are talking about small-scale marketplaces in general rather than specific ones which you have already mentioned. I'm also not convinced about the term 'marketplaces'. Are you sure this is the right word? Shops are not marketplaces. In this context, 'outlets' would be clearer. Note also that you should have a capital 'A' at the beginning, a small 'e' for elephant, and 'stationery' (as in paper goods) is written with an 'e' not an 'a'. "At present, fake elephant cells are primarily found in some small-scale outlets like tiny stationery shops, small self-service shops and kiosks".

Like said above, "some of" must always be followed by a "the something." The simple fix would be to remove the "of" so that the sentence reads: "at present, fake Elephant cells are primarily found in some small-scale marketplaces, like tiny stationary shops, small self-service shops, and kiosks." I added some commas too just so that it reads properly. Hopefully this helps!