What are the segments a NRE Trading Account holder can trade in?

NRI-NRE Account holder can trade in Equity Delivery and Equity F&O Delivery.

An Intraday Trading is not allowed fro NRIs.

Stock holding of an NRI can't exceed 10% in any Indian listed company subject to overall limit for listed equity shares of each company on repatriation benefit basis. Here is the list and limit on stock holding by NRI.