hello, sindhu kadirvel
Ravil gave you very good points and explanation regarding the filters you have mentioned in your post. We have discussed similar topic in your previous post also. However, Ravil explained about the filters for different pulse shapes. I suggest you to go through the links i have given below ↓ . These papers may help you to understand the working of different filters
https://en.wikipedia.org/wiki/Gaussian_filter
http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=6887190&url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel7%2F6878060%2F6886510%2F06887190.pdf%3Farnumber%3D6887190
https://en.wikipedia.org/wiki/Optical_filter