Change of Department at Masters level!

Hello everyone!!
I am currently pursuing a dual degree of Msc(Maths) and BE(Mech).But i wanted to pursue my masters in computer science at a good US university.I have interned in a reputed software company for about 6 months.Some of the queries i have regarding this process are:
1)Will my Masters in mathematics be useful when i am applying to MS in computer science
2)Should I directly apply to MS in CS program or should i apply for MS in mechanical program and then try for branch transfer,which is quite risky as there is always a chance of denial.
3)I have gone through many CS programs’s website and found that one should satisfy certain prereqs if he is from another depatment.I have completed my math prereqs and only left with CS prereqs.Will they allow an internationa; student to take classes for the prereqs.
Thanks in advance

  1. Yes, it will be of great use. They look at your math skills.

    1. You should apply for MS in CS. I do NOT see any reason for you to apply for Mechanical program. You will have to articulate it in your SOP your reason for applying to MS in US.

    2. Yes, you will need to take the CS related pre-requisites only.

    Read this article Apply to Different Major for MS in USA