Q. I want a bike of 200 to 250 cc range having the following criteria 1) the engine should refined that is with least vibrations 2) the pillion seat should comfortable so that old lady can sit comfortably with both legs on one side 3) maintenance cost should not be high.

Brother if you want Such bike you can go with the Jawa bikes because on sports bike it will not be comfortable for women to sit. iF seating is not a problem on high seats than there are many options like FZ25R15 v3 CBRDuke 250

Go for fz25 bro. As it also gets enough mileage and tourque. If you fix a ladies footrest you can make ladies behind comfortable. I get nearly 1000/1500 for maintenance

No fz 25 is not good choice as pillion seat is not comfortable to sit for old lady with both legs on 1 side. i would rater ask you to go for fzs v 3.0 best machine as well and good for pillion riders