It not one year we got this new house, how can I approach this, till
one year, builder's responsibility for any leak/damage right?. How can
I fight with him legally since it is not even a year yet?. Any
suggestion appreciated.
I also went through the new home construction and have many stories of
dealing with the builder. I know how frustrating it can be.

My basement had cracks that were repaired professionally. I researched what
they used and found the same technique available from:

http://www.polygem.com/repair/lcrkit.php

I hope you get things worked out with the builder. Maybe you could contact
the BBB or the Attorney General? If not, the above source should give you a
solution if you need to do it yourself.

Ben