[My query is about PNR 4243928073 for train 12672 NILAGIRI EXP]
It can be upgraded but chances are next to impossible because of this rush season
Upgration is only done when berths are available in upper class at the time of preparing the chart
auto up-gradation scheme is applicable for the waitlisted/RAC passenger of lower class. here your ticket is confirmed in sleeper class. you are not eligible for this scheme.