Summer is the time for a lot of stress amongst school leaving students and their parents. They are terribly confused regarding the college they should join for higher studies. They don't know enough about various options, and that adds to the stress. Media tries to help by publishing rankings of colleges. However, there are several problems with those rankings. Most rankings are only for the top few institutes. Also, rankings are based mostly on perceptions, and on unverifiable data supplied by the Institutions themselves. Many times, they use parameters unrelated to quality (like size). Further, they rank the entire institution, and not a specific program.
Students (and parents) typically look at last year's closing ranks, which means that they miss out on new and exciting places. Or they look at placement data narrowly (even if one student got a Rs. 10 lakh job, the institute must be good). And another bias is that government colleges are better than private colleges. Some NITs are excellent, and a large number of private institutions offer poor quality education. But there are many private institutions with much better faculty profile than NITs.
So, what should students do. The solution is simple. They should do their own research and come up with their own rankings.
In my opinion, the quality of education is primarily driven by quality of faculty. So, if there is only one thing that you want to check in a college website, it is the quality of faculty. You should look for not just the number of faculty members, but also their qualifications, whether they are PhD or not, where did they study, are they active researchers and publishing.
The second most important criteria is the academic freedom that the Institution has. In IITs, NITs, IIITs, and deemed universities, there is complete academic freedom to change curriculum, provide flexibility to students, have their own exams, etc. To faculty, it is very demoralizing that someone else will test what they have taught to their students, and generally speaking (with some exceptions), quality of teaching is better in institutions who have their own exams.
Of course, having freedom does not mean that it will always be used effectively. So, one has to look for more information. Third most important criteria is the curriculum. Do they change it frequently enough. Judging the curriculum will be difficult for a student of, so seek help from a person in that discipline. For example, in Computer Science, if they teach you multiple programming languages, they are more interested in spoon feeding than teaching concepts. In general, and this is counter-intuitive, better departments will have fewer courses in the curriculum. Weaker departments would like to spoon feed you a lot of information in the hope that you can say something when it comes to placement interview. Also, more flexible system would have more electives, and you would be studying topics of your interest. Of course, make sure that those electives are actually offered, and are not just on paper.
Other parameters are less important in my opinion, but do matter. These include infrastructure. How many labs, how many PCs, what is their library holdings, how much is the Internet bandwidth, sports facilities, etc. Another parameter is what happens to the students after they graduate. This includes campus placement, but more importantly, how many of them go for higher education. Remember, the most important skill that college education is supposed to impart is to learn how to learn. If a college is successfully imparting that skill, then it must result in substantial number of students to think about higher studies. And finally, brand equity does matter. Have they got any ranking in any survey. What is the closing rank of last year. Have they been accredited.
Now give weights to these parameters, and start surfing the web to collect relevant information. This is hard work, but remember, you are about to take the most critical decision of your life. Don't depend on others advice alone. Have your own research to back up your decision.