Hi,
Can any one suggest me how to design an low pass filter inductor. the core what i have to use is rod type.i need a detailed design procedure i.e, how to choose a core,wire gauge, number of turns etc...?

 

Start here:
http://www.aade.com/filter.htm
Download the filter design software. Then you'll have a method to develop the values you need with a minimum of pain.

But then comes more pain.

Folks make a good living designing this stuff. If it were easy, everyone could do a good job at it.