hi,
Weird to know about this elusive rule again,although I did meet the requirements for my conversion ,many of my colleagues argued about this so called 50hrs of 100Nm rule not being in the conversion flowchart or anywhere on DGCA site! So most of them unlike me didnt do the Afore said flying.
Anyway its calculated as 100Nm distance -one way or 'to' leg,hence 'to&fro' atleast 200Nm. You need to tabulate them with particulars like date,aircraft callsign,waypoints,landings,duration,distance;which should be same as in your logbook.
If this rule is valid then I guess one also needs to do atleast 2 flights of 300Nm(again calculated as above).