IBM Tusteer
 

Is the IBM Trusteer software available for installation in Linux Mint 17.3 or 18 Firefox? Thanks!

No idea, since that software suite has at least five different products in it, and you don't say which one you're asking about. And, since it's a commercial, pay-for product, the best people to ask would be IBM...have you tried that? They have a page on their website dedicated to the Trusteer suite.

IBM Trusteer
 

Look at RAPPORT.TRUSTEER.COM I guess technically it is no longer IBM's.

Technically they claim no. https://www.trusteer.com/en/support/supported-platforms
Might be possible to use some android deal on linux to use their android ports or SDK.

IBM had it listed as theirs. Only cost them $1B. if you believe wiki.

"Trusteer is a Boston-based[2][3] computer security division of IBM, responsible for a suite of security software.[4][5] Founded in Israel in 2006,[6][7] Trusteer was acquired in September 2013 by IBM for $1 billion.[8][9]"