Senior Citizen is just a concession applicable to male (60+)(40%) and female (58+)(50%). They can either travel single or in groups.
If they travel single, system would automatically place them in vacant LB Quota; i.e. they would be eligible for both LB+Concession at the same time. Else they would be placed in GNWL (When LB Quota runs full).
If any LB gets cancelled in the meantime, then it wont be released. The vacant quota will be released only during charting.
There...
more... is no guarentee of allotting the vacant LB's under this quota to the one who are actually eligible for it. Thus, if you are placed in GNWL, kindly apply for the same to the Station Master/Charting Officer through a letter.
Female(45+) Travelling alone, Pregnant women (May or may not travel alone), Handicapped people (May or may not travel alone) are also eligible for LB.
Note: Handicapped people are also eligible for concession.
Note: There in no concession in Tatkal, Yuva and Garib Rath.