Hi Anand,

The reality is they dont teach IOs or Andriod app developing in either IT or CS at the colleges. Most of the students learn it on their own or through their clubs in colleges, or by joining classes. Primarily if you know JAVA, you could learn Andriod app development on your own and for IOs, you may need SWIFT. Its not hard if you know the languages. So primarily if you are interested in Andriod development, IT can be considered as IT is primarily software oriented while CS gets a bit into the hardware part of learning. 

Check the syllabus or cuticulum of the college and institute before you apply. If you have JAVA, you can build on that. All the best!