Hello Aspirant,

I'm stating the pros and cons for taking Computer science in 11th. 

Disadvantages

• It has a very long and Exhaustive syllabus
• Mugging up doesn't work like it might in other subjects like physical education and Hindi etc
• You need to be good at computer knowledge of previous classes especially 9th and 10th
• Some topics dwmand high standards of understanding and mathematical skills for topics like stacks, queues, lists and arrays
• It demands a lot of time and hard work. 
• Practice demanding. 

Advantages:

• If you pursue PCM then surely you are going to some science and technical field. Having basic knowledge in computer science will surely help you.
•  You can learn programming and can make awesome websites and applications for mobiles and web if you are interested in that.
•  If you go for engineering then knowledge of computer science can be a great help.
•  Now comes the scope, actually this would be senseless of talking this because there were not as many jobs and opportunities as there are today.
• Most of students try to get admission in computer science (like in IIT most want CSE) . So there are lot of people in CS field but there is a shortage of talented people still.
• And as you will be having PCM with you but still it won't affect you study of other subjects

I hope it helps. All the best.