Hello mukund,
I would suggest you to download the 30 day evaluation trial version of optisystem 14 and try to run your simulation and regarding your later query , i want to mention that optisystem has recently added that to the BER test set. You can plot BER versus any parameter in the system. NOTE: this is in the BER test set, not the BER Analyzer. For the BER Analyzer, you would have to create these plots by hand (by copying/pasting the results into a program like excel).
Rgeards