Is the Tabligh Jamaat's system of tableegh Sunnat?

Answer

The system is simply permissible. As long as it is retained within the limits of the Shariah, it will remain permissible. Just as printing kitaabs, teaching in schools/madrasahs, using the internet for propagation, etc. are permissible so too will any new system of ta'leem and tableegh be permissible if kept within the limits of the Shariah.