Interesting question Shabbir. I can think of following possible ways to target students based on mentioned criteria, i.e. location, type of education/stream, types of institutions:
Facebook Ads: Facebook ads give you flexibility to target students from particular type of institutions from a defined location.
Google Adwords: While it's not a direct targeting but if you can identify relevant keywords, which ensure that people searching for those keywords are likely to be your audience (i.e. student from certain kind of institutions), you may be able to see good conversions. I am assuming that you've flexibility in terms of number of institutions of a particular type vs having a defined list of specific institutions.
Education Publishers: Some of the known educational publishers such as Careers360, Shiksha, CollegeDekho, CollegeDunia can help you reach out to your target audience through display ads, emailers.
Groups and Discussion Forums: Participating in relevant Facebook, LinkedIn & Yahoo groups and discussion forums such as Quora, Pagalguy is another possible way to reach out to students.
The time these channels will take is a function of initial research, your communication and the type of resource you can devote for these initiatives. Moreover, you will have to go through couple of iterations before you can conclude if a channel is relevant or not.
Hope this helps!