Hello Gihan

Welcome to the forum! Don't worry about your English (which is excellent btw), many of us here speak English as a foreign language

Gihan Saminda Pathirage:
Metta which seems useless now because I was thinking when meditating.
Thinking while meditating is not necessarily bad, particularly in the beginner stages... and the very advanced ones. But it is better to cut back on it in the intermediate stages

Either way, if you found no benefit in metta at the moment, I think it is perfectly ok to drop the practice

Gihan Saminda Pathirage:
Then few months ago I met a great teacher who changed my path, he taught me that this is not the reality and he told me to not to belive in those concepts such as rebirth. Then he provided me some techniques to meditate (vipassana).
Could you tell us more about the vipassana instructions you have got? I am curious. The most famous ones in the Theravada tradition are probably Goenka / U Ba Khin body scanning, Mahasi Sayadaw choiceless noting, and Forest Thai. Is it any of these?
Gihan Saminda Pathirage:
Last week I started to do vipassana, and few days later I got a feeling like vibrating all over my body and it lasted few days.
It sounds like the Knowledge of the Arising and Passing Away, particularly if you were doing body scanning. If you have never heard the term before, it is udayabbaya-ñana in Pali, the fourth of about 16 stages to Stream Entry (sotapanna). It is hard to confirm by forum, but, if it is, it is called informally "the little enlightenment", so it would be reason to celebrate

Gihan Saminda Pathirage:
Also I had a small ache between my eyes. I got scared and I immediately stopped mediatating for few days.
Can you elaborate on getting scared? Give us more details? Depending on the answer, it might be either be the sixth ñana, Knowledge of Fear (bhayatupatthana-ñana)... or simply a case of you having gotten scared by something that should not have scared you.

The ache between the eyes... no idea, it could just be straining. Probably someone on this forum has experienced it too, never happened to me.
In any case, if what you experienced was, indeed, the Knowledge of the Arising and Passing Away, a phase in which meditation feels difficult, painful, stagnating, scary, or makes you sad is very likely. Nothing to worry about, with correct practice it can be dealt with, but it is something that is good to know about.
Gihan Saminda Pathirage:
Then later my mind changed and I started to meditate, now I do not have vibrational feelings anymore.
It is normal. That is a transitory phase. It is perfectly fine to enjoy the vibrations while they last, but you should absolutely
not associate progress with getting vibrational feelings on your body.
Gihan Saminda Pathirage:
It's hard to find a good teacher on Sri Lanka, because the things they are teaching is inttelectual.From Books. Not by experience.
You've come to the right place. Lots of practice here!

Gihan Saminda Pathirage:
We have many vipassana meditation centres also but none of teachers seems have experienced the sotapanna.
It is a common problem in certain traditions, sadly. You can get Stream Entry working on your own. This e-sangha is here to help!
Gihan Saminda Pathirage:
1. Am I on the right track ?
Hard to say without more details, but if you share your practice, you will get lots of advice here.
Gihan Saminda Pathirage:
2. How long will it take to get in to sotapanna ?
Impossible to predict. Some people get it spontaneously, by accident so to speak. Some work on it for months, some for years. With smart and intensive practice and good instructions, months might be a reasonable goal. But it depends on putting in the right number of hours, the right kind of effort, finding the technique(s) that are best for you, and so on.
Gihan Saminda Pathirage:
3. I am a student and I have to study about 10 hours a day. I can only meditate for like 4 hours. Is this enough ? Can I do that with my studies ?
Four hours a day is really good practice! If you practice correctly you can get a lot of progress from that. Absolutely keep doing your studies! There is no need to renounce your life, interests, hobbies and friends to cultivate meditation. (Actually, I would worry about the opposite, with 10 hours of study + 4 of meditation, do you find time for friends, family, some physical activity, and so on?)
If you want to know about the stages of progress towards Sotapanna, you should read Daniel Ingram's Mastering the Core Teachings of the Buddha, which is available for free here (400 pages):
http://static.squarespace.com/static/5037f52d84ae1e87f694cfda/t/5055915f84aedaeee9181119/1347785055665/if you are burning with impatience to know about these maps, a much shorter presentation (40 pages) can be found here in Mahasi Sayadaw's book The Progress of Insight, the second link here:
http://www.saraniya.com/page/ebooks/ebooks-mahasi-sayadaw.htmlThe first book in this link, "Practical Insight Meditation" is also pretty nice (20 pages).