I believe that any comercial kit can help you. 

Dear Karuppiah 

Finding and employing a right method to extract RNA depends on the application in which you are going to use that RNA. Various protocols can be employed to extract RNA from plant leaves such as Tris-LiCl, Trizol or RNeasy Midi PEG and etc. In fact, RNA would be checked for degradation prior to being used for any application (e. g. RT-PCR). Factors like obtaining a good yield and quality with low cost are also important to be considered. 

Hope my answer can help you,

Good luck

Preferred will be kits. If not, snap freeze the sample in liquid nitrogen and process using TRIzol.

This protocol works fine:

http://apsjournals.apsnet.org/doi/pdf/10.1094/PDIS.1997.81.2.222

1) Trizol by invitrogen works best in our hands. or

2) buy Commercial QIagen kit...

Hello

Please see the attached papers.

Dear Karuppiah

The study at below showed that the improvement of a CTAB‐based protocol allows the rapid isolation of high‐quality RNA from grapevine and many woody species.

Article A Rapid and effective method for RNA extraction from differe...