Going from Hindi to Malay (Bahasa Melayu) has a composite linguistic distance of 87% (heuristic estimate). Below is the dimension-by-dimension breakdown.
Shared vocabulary, cognates, and loanwords.
Morphology, syntax, word order, cases.
Shared sounds and phoneme inventory.
Devanagari → Latin/Arabic
Indo-European ↔ Austronesian
The 5 languages with the lowest linguistic distance from Hindi:
A quick 3-question check between Hindi and Malay. No signup.