You need to use the industry code that works with TurboTax. 611000 is not a valid code, but you can choose one that suits your type of educational services from the latest codes in the NAICS.
Examples can be seen in this link: http://www23.statcan.gc.ca/imdb/p3VD.pl?CLV=2&CPV=611&CST=01012017&CVD=1181576&Function=getVD&MLV=5&TVD=1181553
The Turbo tax industry code for education is 611. Yet when I put that in, as I am self employed in education as well, they say I need a six digit number. The six digit number on the link provided to find CRA industry codes is 611000. They still do not accept this. Any suggestions? Cannot file until this is fixed.
Most probably it is 611710 for Education support and Service
Please check this link for NAICS codes since this is what TurboTax uses for industry codes:
I hope this was helpful