Can one pursue a Master's in Computer Science without a Bachelor's degree in Computer Science?
Yes, definitely! This is a very prevalent trend in the Indian Institute of Technologies or IITs. Many of the students who come from various backgrounds like Mechanical Engineering, Electrical Engineering, Mining Engineering etc. they opt for Computer Science and Engineering in the IITs. If you crack GATE in the CSE subject, then no one can stop you, however you'll have to convince the interviewer panel that why you should be selected in the place of a person who has completed his bachelors in CSE. If you manage to do this, then there is no reason why you'll not be able to get admission.
Hope I have answered your question. All the best!