Should i pay fee and gic by the agents or directly from the bank
Firstly, GIC needs to come out form your own account and which bank have you opened your account with Scotia or ICICI Canada ? I have opened mine with Scotia and it strictly says the account needs to be in your name otherwise it will be rejected. I think, if you have opened with ICICI Canada, you can use somebody else's account to pay but I still wouldn't do that. Joint account maybe acceptable but you need to ask them. The reason why its better to transfer the money from your account is that when it gets rejected, you will get it back in your account but if the third party has paid it for you, you will have trouble locating your funds since the money is yours and account belongs to somebody else. Hope this makes sense to you.
Secondly, I would suggest you to make your own tuition fee payment by going to the bank and get to know what exchange rates they are giving, its negotiable since you are paying large amount. If you have trouble visiting the bank then you can rely on the agent to make the payments on your behalf but make sure you know how much they are charging you in terms of exchange rates? Normally, they will charge you a higher rate than your local banks and this is from my experience and on top of that they will charge your GST of 18%. Certain banks have flat rates irrespective of how much money you send so you can at least save some money for yourself. Tuition fees can also be paid through Western Union but I would suggest you to go and visit them first.
I hope I have given you enough information since they are based on my experience and what I have read in this forum.