I had a struggle finding a NTFS read/writer that works after downloading OS X 10.11 El Capitan.
This morning I found at Seagate.com a link for the Samsung drive NTFS for mac (Paragon app downloaded as NTFS_for_Mac_14.0.456), which has worked beautifully.
The link is in Portuguese but you can Google Translator it to make sure i'm not driving you to any fishing site or whatever and there's probably a version at Seagate US.
http://www.seagate.com/br/pt/support/downloads/item/samsung-ntfs-driver-master-d l/
Before I could find it, I had a little help from the IT guy from work who taught me how to mount the drive using the Terminal app from the utilities folder which already comes with the OS and can be found on the Applications folder.
You can open the terminal and use the command sudo su:
With your portable device plugged, type:
Sudo su <return key>
enter your mac password <return key>
./montaNTFS <return key>
And Bam! Your HDD hard disk shows up at your desktop.
But it only works as read, not read/write.
I hope it helps.
Sorry for the non native English.