I have done Btech in ECE and I have 5 years of work experience as a senior data engineer in an MNC. Can I get admission in University of Toronto without GRE.

No, GRE is not compulsory for admission to the University of Toronto. It is optional for the University of Toronto, but it's highly recommended that you submit with a good score, as it adds credibility to your application. More than the university, the requirement for GRE depends on the specific program that you are applying to at the University of Toronto. It’s better to check your program's website.

• The website of the University of Toronto for the Department of Electrical and Computer Engineering stated that a GRE score is not required. 
• The Civil Engineering Department also doesn't require the GRE. 
• The website of the Department of Mechanical and Industrial Engineering also does not require it. 
• The Department of Chemical Engineering and Applied Chemistry did not state anything about the GRE requirements. 

Thus it can be safely concluded that there is no GRE requirement as such for MS in the University of Toronto. However, it is always recommended to have a standardized exam score like GRE for Graduate studies as this will improve your chances of admission.