Hello Suresh,
Thank you for contacting National Instruments.
If you are using NI-DAQmx, you can use a channel property node to retrieve the cutoff frequency of your input filter. Please see the attached screen shot for details.
In Traditional DAQ, use the AI Parameter.vi located under NI Measurements >> Data Acquisition >> Analog Input >> Advanced Analog Input >> AI Parameter. See the screenshot below for details.
Let me know if you have any further questions.
Sincerely,
Sean C.
Applications Engineer
National Instruments