Hello Darshan,
You cannot filter the signal without some delay. You can choose the low pass filter appropriate for your purpose with some delay. It is not possible to perform a zero-phase filter in real-time because a zero-phase filter requires filter coefficients that are symmetric around zero. That means that the filter is non-causal, or that current output depends on future input. This of course is not possible in the real-time case (simulink) and can be faked as in the case of filtfilt in MATLAB during post-processing.
You can even post process the signal by Compensate for the Delay Introduced by an FIR Filter or passing the signal again through a conjugate of the filter used in the simulink in the first place.
