Visa type change- Tier 2 ICT to Tier 2 GENERAL

[RDG]

Hi,

I am currently on a Tier 2 General Dependent VISA and would like to know whether Myself and my Spouse am eligible to apply ILR.
I am though not sure if and when I would be eligible to apply and hence appreciate if my case details below could be reviewed and
advised accordingly please.

1) I entered UK for the first time on 30th Jun 2010 on a Tier 2 ICT VISA. Spouse came as my Dependant of Tier 2 ICT.
2) I went back to India on 23rd Jun 2012 to 14th Sep 2012.
3) Returned to UK second time on 14th Sep 2012 on a Tier 2 GENERAL(Employer Visa) Dependant. My Spouse has become primary for TIER 2 GENERAL VISA.

I had the following leaves of absences from the UK till date since the time I entered.
- 83 days in 2012 (FRom 23rd Jun 2012 - 14th Sep 2012)

I would be grateful if someone could advise on the following:
- Is change in VISA Type is being eligible to apply for ILR?
- When is the earliest I could apply for my ILR?
- Lastly, what are the supporting documents that I need to produce for my ILR application?