Hello Sabu,
It's true, you didn't describe your problem at all. By "filter out", I understand you want to remove DC. If that is the case, you should use a high-pass filter and not a low-pass. In that case, the sampling frequency should be at least as high as two times the signal bandwidth fs= 2*BW.
If what you want is actually the DC, then use the low-pass. By default, I would advice you to use fs= 10*fc. If the high frequency noise is too high, the alias might produce an ofset on your DC signal.
Good luck,
Oscar