Yes, you can use MTCaptcha as a fallback in situations where reCaptcha fails to load (eg sometimes in China, or for users behind corporate firewalls that require specific IP white listing ).
Sample javascript fallback code can be found below on Github.
https://github.com/mtcaptcha-public/MTCaptcha-Javascript-Fallback-from-ReCaptcha
See Also
To learn how to IP Whitelist MTCaptcha if needed for secure networks, see FAQ - Whitelist MTCaptcha Service For Firewalls