Boot from ramdisk
In some of the links it is mentioned that NAND disk image is used for final production based board and during development NFS or ramdisk/init.d file system is used. In my final production board , if I put my file system as ramdisk some of my parameters which I want to save in file system will lost during booting. So is there any way out through which I can store parametes for file system along with my data on CF card
Not really sure what you mean with production board (except for film making), but the RAM disk, and I have a feeling you mean 'Initial RAM disk', or initrd, no that doesn't store anything. It just makes your RAM behave like it was a harddisk, but storing things on it between reboots is impossible.
That said, you can mount any other filesystem that is supported by the kernel, either compiled in or loaded as module, from the RAM disk. Just like you would otherwise store something on an external media.
You can for example work on the RAM disk, but store everything on an USB stick, an internal drive or some network drive (NFS, SSHFS, scp, Samba) just as long as the kernel knows how to handle the filesystem. A FAT formatted USB stick (most are FAT formatted by default) should not pose too much of a problem?