v3.26.1
Material accounting policies (Details 1)
 12 Months Ended
Mar. 31, 2026
Computer software [member] | Bottom of range [member]  
Statements [Line Items]  
Amortisation method, intangible assets other than goodwill 1
Computer software [member] | Top of range [member]  
Statements [Line Items]  
Amortisation method, intangible assets other than goodwill 3
Cable Capacity [member]  
Statements [Line Items]  
Amortisation method, intangible assets other than goodwill 12
Other intangible assets [member] | Bottom of range [member]  
Statements [Line Items]  
Amortisation method, intangible assets other than goodwill 3
Other intangible assets [member] | Top of range [member]  
Statements [Line Items]  
Amortisation method, intangible assets other than goodwill 5