I am not sure if my NAS even supports BTsync, here are supported devices http://help.getsync.com/hc/en-us/articles/206215185-Synology#dl
And here are architechtures https://github.com/SynoCommunity/spksrc/wiki/Architecture-per-Synology-model
So my 212j has 88f6281 (88f628x) architechture, what ever that means, but it does not appear in above list.
... nvm, found it ...