I have a signal of about 100 mV peak-peak with nearly 10mV offset. I tried removing offset using active second order high pass filter but can't remove it fully. I observed that if I give a larger signal to filter using signal generator (5V peak-peak with 1V offset) my filter removes the offset properly. Is there any relation of filter designing with signal magnitude.Can you refer me to some god high pass filtering techniques to remove DC offset. Circuit of high pass filter I used is given below

 

Just use a series coupling capacitor (RC high-pass filter) to block the DC.
What is the signal frequency?

 

Just use a series coupling capacitor (RC high-pass filter) to block the DC.
What is the signal frequency?

Signal Frequency is 50 Hz.

 

The schematic says that you are using an LM741 which can easily have several millivolts of offset. You can null the offset with a 10k pot connected to the offset null pins as shown below.

That amplifier was designed 40 years ago and there has been a lot of progress made since then. Unadjusted offsets down into the microvolts are now not expensive.

Edit: Just saw that you said the signal is 50 Hz -consider using an OP-07.

 

The schematic says that you are using an LM741 which can easily have several millivolts of offset. You can null the offset with a 10k pot connected to the offset null pins as shown below.
View attachment 141765
That amplifier was designed 40 years ago and there has been a lot of progress made since then. Unadjusted offsets down into the microvolts are now not expensive.

Edit: Just saw that you said the signal is 50 Hz -consider using an OP-07.

Sir: We have to remove the offset using potentiometer. Like the circuit given below

 

So your problem is solved?