I have done preparatory course and b.com from ycmou without 12th .can i take admission for bsc(bis) in ycmou ?

With ycmou I think you mean Yashwantrao Chavan Maharashtra Open University. Actually, for most of the bachelor programmes in their Computer Science department, following is the eligibility criteria: 12th Standard OR equivalent OR MCVC OR HSC vocational OR 2-year ITI of any trade whose eligibility