Confusing ,advice plz

Hello,
I came to UK on 12 th oct 2010, soon after I got the tier1 visa stamped on 6 th oct 2010. But had to leave after a month to India since I did not secure a job on nov 16th 2010.Again came back on April 2011 to uk and have been present here till now with no absence.Got my 1st extension and have a visa from oct 2012 to oct 2015. So m I eligible for iLR in 2015?total absences are 150 days to 160 days .my dependants came on oct 2011 and are in UK presently.
With all the ext closing on April 6th 2015 i will be
Applying for my 2nd ext this year end.my question is can I
Take a chance and apply for my ILR next year itself since I'm within 180 days period of leave.i m doing this since if I m granted ILR next year ,my dependants can apply too for ILR next year.else I need to wait till April 2016 and apply for ILR and next year take 2nd extension for my dependants ,for which I will be totally ripped since the fees is soo expensive:(
Need some advice plz
Thanks

You are fine for ILR in October 2015, since your total absence is less than 180 days in the 12 month period. Your dependents are good to apply with yourself as well.

You dont need another extension in April 2015.
Read Calculating Continuous period for ILR in the UKVI site.

Thanx a ton

I am in the same scenario 161 to 172 days in the 12 month period (Leaves are: 1 nov 2010 to 12 April 2011 and 27 May 2011 to 07 Jun 11). So in the above case and my case do i need to provide an explanation / reason why I was out?

Thanks in advance.