External　debt　correlation　and　the　sustainable　economic　development　pathway　within　the　South　Asian　sub-region　is　analysed　in　this　research　paper.　The　longitudinal　root-analysis,　the　pooled　ordinary　least　square,　quantile　estimation,　and　output　estimation　were　utilized　to　evaluate　the　data　obtained　from　the　World　Bank　Development　Indicators　for　the　period　of　2000-2018.　We　discovered　that　total　external　debt　and　external　debt　services　affect　39%　plus　31%,　respectively,　after　the　robust　regression　analysis　was　carried　out.　Besides　that,　the　findings　demonstrate　direct　expansionary　impacts　of　fiscal　policy　crosswise　in　developing　economies　within　the　study　timeframe.　Remarkably,　the　advancements　in　state　establishments　encourage　the　＂gathering　impact＂　of　fiscal　policy　implementation.　The　findings　depict　that　the　entire　circumstances　set　a　stiffer　restraint　on　public　expenditure,　indicating　a　self-losing　fiscal　austerity　situation　which　entails　the　impact　of　the　company＇s　liabilities.　Inversely,　the　unrestrained　countercyclical　policy　bars　the　knock-on　impact　of　external　problems,　resulting　in　an　improved　economic　system　activity　performance　as　well　as　decreasing　the　probability　of　economic　predicaments　after　COVID-19.