Can i be a good pianist? What does my future expect?
As it has already been said, it depends on you.
I am the last person who can know and talk about it, but I can tell you the following things:
I don't know what being a good pianist means for you. A good pianist is not necessarily a famous pianist and a famous pianist is not necessarily one of the best. The fact that you started taking piano seriously at an older age than the ordinary maybe means that you won't probably become famous and world-known at 18 or 20. And also, big careers (these of big names in the world of piano, and music and arts generally) sometimes depend not only on their talent and ability, but also on circumstances.
As for your practice, it's not the amount that makes it efficient, but the quality. For example, someone may practice for 6 hours a day, but he may do almost nothing. When you practice, you must be aware of what you want to achieve and how you can do it. You have to explore the piano and the music in general. After your practice, you must be tired mentally (of your concentration and hard work) and not physically. Of course, being exhausted by practicing 12 hours a day (ok, I exaggerate, but some have done it) can bring out the opposite results!
For the time being, I can't say more about practice because its a big (maybe endless) subject on its own!
My advice:
Do what you like! If you are passionate for the piano, do your best!
If you want to become a professional concert pianist, then you should try hard to achieve it. Nowadays, competitions, masterclasses and interconnections play an important role on a pianist's career. I don't say that this is right. Many of the old great pianists hated competitions and were opposed to them (Horowitz for example). But world changes. Commercialisation of art makes it necessary...
Also, talk with your teacher. Let him know what you feel and what your intentions are, and possibly, he will help you by showing you the path. However, you are the person who will cross it!
Hope I've been of some help!
Evitaevita
P.S. Personally, I believe in this:
If you want something, if you really do, then you can achieve it!