@ Plz elaborate on the issues and if possible with posting of relevent rules ....
@ General unreserved ... half tickets... (without any full tickets) are easily available at the counter without much of a trouble. No questions are even asked. Further .... like in Mumbai suburban train ... adult having Rly pass and need half ticket only for minor... it's easily available from the counter. Keep apart, ticket booklets are available and minors do easily travel by punching the appropriate denomination value ticket. ...
more...

a) Scenerio ... A male/female passenger having confirmed booking later wish to take his minor child alongwith, then as per your reply, it's not possible at all to book the ticket. Per your reply, in this case, fresh booking is invited for all the three passengers and a ticket already booked for 2 adults needs to be cancelled !! Is it so ?
b) Second scenerio.... Passengers got two PNRs ... confirmed booking each... for 2 adult +1 minor child and later wants to cancel the PNR-1 ticket for 2 adults and wants the lone minor child of PNR-1 to travel alongwith PNR-2 passengers... then in that case what is the solution ... ? As per your reply... although the minor child can travel with PNR-2 passengers (responsible persons) ... then how to go ahead in such cases.... ?
c) third scenerio .... 2 adult + 2 minor child passengers want to do booking from Mumbai Central to Ahmedabad and wish simultaneous booking for onward journey from Ahmedabad to Udaipur for only 2 adults .. (without minor child) ... for telescopic fare purposes, is it possible ? (Since as per your reply .. seperate /independent booking for 2 minor child from Mumbai Central to Ahmedabad won't be allowed).
d) fourth scenerio .... 2 adult + 2 minor child passengers want to do booking from Mumbai Central to Ahmedabad for 2 adults and from Mumbai Central to Vadodara for 2 minor child .. in this case, definitely there will have to be two seperate bookings but how about booking minor childs in this situation ?
Shall the person have to do booking and spend extra by booking for all 4 from Mumbai Central to Ahmedabad ? Or do two bookings ... first booking from Mumbai Central to Vadodara for all 4 and then again booking from Vadodara to Ahmedabad for 2 adults... ?
@ There can thus be number of scenerios. Plz post the relevent rules in regard to minor travelling ....
@ Other bloggers are too invited to submit their views on this. Good wishes.