How do you say necessary in Hindi?
— ज़रूरी (zarūrī)

Generic synonyms for necessary in Hindi
thingवस्तू (m) (vastū); चीज़ (f) (cīz)
Specialized synonyms for necessary in Hindi
mustचाहिए (cāhiē); पड़ना (paṛnā); (hōgā)
needज़रूरत (f) (zarurat)
wantचाहना (cāhnā)