Problem with tier 2 dependant App- Experts kindly advice

[orthodoc]

Dear Friends/ Experts,
I need an advice regarding a pretty complex problem. A prompt and sound advise can be great help to me.
I am here on a tier 2 visa, when i was applying for my tier 2, my sponsor provided me with the COS stating that my duration of work as 2 years, though i had a contract of only 6 months with possible extension.
I applied visa as per the info provided on COS and got visa for 2 years.
Now I am putting in an application for dependants. I am pretty confused about the dates i should fill up in my dependants application regards duration of my work. As per my cos its 2 years, but the actual contract they made me sign is for 6 months only and they are willing to provide an employer support letter saying that my present contract expires in 6 months time. So now my options are
1. Fill up dates on my dependants forms as per COS, provide salary slip , hank statement but skip the letter from sponsor
2. fill up the actual dates saying my work ends in 6 months and also provide the sponsor's letter confirming the same.
Thank you

[orthodoc]

can someone kindly advice....

[orthodoc]

Hi,
Just to add upto my query, how essential is a tenancy agreement for making a tier 2 dependant application? I have clearly mentioned in my letter of support that I intend to get appropiate family accommodation, once a date of arrival has been decided. It would be great if someone who applied recently for t2d can give an advice on this.
Thanks