Not able to use rooks properly While playing a game, I observe that I am not able to use my rooks properly. The reason is that I am not able to bring them out earlier as they occupy the corner position. This gives a lead to the opposite player. 

Can someone tell what is the best opening moves for rooks if I want to use them for defending my two middle pawns?
In general, it is not easy to develop rooks during the opening per se. Not only it's not easy, it rarely is a goal of the sound opening.

In some references, the opening ends, when minor pieces (bishops and knights) are developed and rooks are connected. Therefore, it is highly likely that you are already talking about the middlegame rather than the opening.

Now, regarding the general use of the rooks. Rooks are good at open files (or files that are likely to become open). Instead of having the goal of using rooks to defend the two middle pawns, I suggest looking for good files for the rooks, whether it is in the center, open C-file, or, soon-to-be-open A-file.

To get the best of your opening (again, there are always exceptions, established theory) in general, look at developing your minor pieces at active squares, castle your king, connect the rooks, and place them at strategically promising files.