You need to analyze your overall profile to gauge your chances of getting into a tier-1 MiM program.
You CGPA is lower than what’s expected in the competition, but you can compensate for by your work experience, extra-curriculars and any special recognition that you may have received.
An exchange program to China definitely adds value to your profile, so make sure that you highlight the competencies you gained via this global exposure.
You have mentioned that you have done 2 internships, but you have not stated the company names. Remember,a global brand name like Google,McKinsey,Accenture,etc.adds more value to your profile.
MiM is branded as a pre-experience degree, but almost every B-school encourages applicants to have a little work-experience ranging from 3 months to a year.
Since you have explicitly mentioned that you want to aim for Tier-1 MiM programs, building on your work experience (Especially with globally renowned brands) will definitely give you brownie points.
It is your personal call whether or not to take a preparation break for GMAT.
The expected GMAT for Tier-1 programs is around 650+, which is fairly achievable while working full-time. (The average time to achieve a score like this is around 3 months.)
However, you are the best judge of your capacity so do a thorough analysis of your timelines before you make a call.
As you want to take up an MiM program in canada, it is a good idea to read about its prospects here:
https://www.mim-essay.com/review/masters ... in-canada/ It will give you a concrete idea on the top canadian B-Schools, average fees, living costs and post-study work opportunities.