wpa_supplicant is able to handle EAP-TTLS, but whether Network Manager can generate a proper configuration file is another matter entirely.
Here's a blog post from someone who managed to get EAP-TTLS working by manually creating a wpa_supplicant configuration file.
Please note that you may have to disable server certificate verification; the combination of EAP-TTLS and MSCHAPv2 (which makes no sense as EAP-TTLS is encrypted and MSCHAPv2 is insecure anyway) means there's probably an MS server at the other end, and it most likely has a self-signed certificate that no-one outside the Windows AD domain can validate.
Also, if you Google for more hints and tips, be aware that EAP-TTLS != EAP-TLS. You do NOT need to obtain a client certificate.
