Hi Sanil! Welcome to LinuxQuestions!
I don't know if your /etc/lilo.conf (the configuration file for lilo) contains entries for both Linux and Windows 98. But following this procedure, you will at least be able to boot Linux and then we can fix your Windows loader later. (The Windows partition will not be damaged, just not accessible.)
o Boot with your RedHat installation CD and type 'linux rescue' at the boot prompt.
o You will now get to a command shell and there will be a text telling you where your Linux partitions are mounted. (/mnt/ something)
o Change root to that directory.
~> chroot /mnt/<the directory described above>
o Possibly edit your /etc/lilo.conf file
o Run lilo
Do you want more help or do you know how to edit your lilo.conf file?