How to become a Theoretical Computer Scientist I am a computer science graduate from India. I have worked in a reputed software company for 10 months only to discover that my area of interest is something else. So I resigned from there and I am presently preparing for GATE 2014 which is due in a few days. Now I have the following doubts in my mind : 
 1. Is it sufficient and necessary to get into a reputed college in India through GATE ? 
 2. Are there any alternatives to pursue a career in Theoretical CS ? 
 3. How about foreign universities for this career path ? 

Please provide me some career guidelines. Thanks in advance.
You asked three questions:


Q1 is really out of scope for this forum: it relates to GATE and how you gain admission to Indian grad schools.
Q2 I interpret as "do I need a graduate degree to study theoretical computer science". In general, of course the answer is "no", but the discipline of studying at the grad level (with the access to professors and other grad students) is hard to replace with a self-study unless you're supremely motivated. 
Q3: of course you can apply to foreign universities for graduate studies: again, you might find it useful to peruse academia.stackexchange.com for a plethora of information on how to go about doing this.