Here's my experience.

This morning I looked at the weather, it said it will be a bright sunny day and then looked at the Google directions from my place to the destination. Google map shows you 360" view of the destination location. Guess what? That picture showed me the parking garage next to 55 St. Clair Ave building.

So with that in my mind, I went with the "Car" option and the parking was so easy. Next to 55 St. Clair Ave, there's Sobeys grocery store which has both customer and public parking (underground garage). If you shop in Sobeys, then the parking becomes free.

I had to spent about 90+ minutes at the immigration place to get my PR card and on my way return to the parking spot, I bought some bread at Sobeys, my parking has become totally FREE.

So it all worked out very well for me without spending extra time on commute on train or bus or even hefty taxi charges.

Thanks all who replied to this thread. I'm sure my experience will help someone who wants to go to this place in the future.