You may refer to the table below to find out which Reolink cameras can record to NAS.

Models which can record to NAS
RLC-410; RLC-410-5MP; RLC-410S; RLC-411; RLC-411-5MP; RLC-411S; RLC-411S-5MP; RLC-420;RLC-420-5MP; RLC-422-4MP; RLC-422-5MP; RLC-423; RLC-423S; RLC-511; RLC-520; C1; C1 Pro; C2; C2 Pro; E1 Pro; E1 Zoom; RLC-410W; RLC-410W-5MP; RLC-410WS; RLC-411WS; RLC-411WS-5MP; RLC-422W; RLC-423WS; RLC-511W;RLC-422W-5MP; RLC-510A;RLC-520A; RLC-810A;RLC-811A;RLC-820A;RLC-822A;RLC-1220A;RLC-510WA;RLC-511WA;
Note: Since E1 Pro doesn't support FTP function, it's not supported to connected E1 pro to NAS using FTP. 

If you want to know more about how to have Reolink camera records to NAS, you may refer to the article below.

How Can I Have My Reolink Camera Record to My NAS?