You can move to Earth explorer link where you can select the satellite and in the additional criteria section you can find the cloud amount of particular image

Hi

You can use this website   https://ladsweb.nascom.nasa.gov/  

You can obtain differents MODIS products.

Additionaly, FTP site of MODIS L2 atmosphere data is following,

ftp://ladsftp.nascom.nasa.gov/allData/6/MOD04_L2/

Giovanni, providing L3 data, is another nice DB ! 

http://giovanni.gsfc.nasa.gov/giovanni/

Thank you all for  given me the required links.