one of the best low market cap coins 2021
1. Matic Network (MATIC)
2. Zilliqa (ZIL)
3. Blockstack (STX)
4. SiaCoin (SIA)
5. Docademic (MTC)
6. SelfKey (KEY)
7. Basic Attention Token (BAT)
8. Linda
I think coins that have low capitalization have a very big risk compared to altcoins with high capitalization, but from the list you mentioned, I highly recommend matic, even though it is still very low, but this coin has a high chance to increase in the future, because the demand and users of matic is increasing from time to time.