Calculation of Tier 2 6 year limit

Hi

I am on a T2 ICT Long Term granted on Jan 2013. So I have been here for 3 years now. I am planning to find a route to get an ILR. If I get a T2 General for my wife and I become her dependant, then can we stay on that Visa for another 5 years and get an ILR?

I have read there is a 6 year limit on T2 visas, details of which is not clear to me. Will that limit apply after we switch to T2 General in above case and I can only stay for 3 more years?

1. Yes, if the rules do not change in those 5 years.
2. The limits, if any applicable, on period of grant is calculated as per duration of stay of the "principal" migrant under Tier 2.