Write as you pronounce Hindi is preferred anusvar free and with म् न् for readable Roman transliteration.
These newly added ॅ ॉ sounds not found in Sanskrit text may replace lots on nasal sounds in speech
half म् with p,f,b,bh and with m(some times) and half न् with rest of consonants.
अं > am / ang..........ambar.........
ऐं > aim / sing..........eim
गं > gam / gang.......gamble
सं > sam / sang........sant/samp
यं > yam / yang.......svayamvar
इं > im/ing ...............din/dimpal
उं > um/ung..............uunt/uumf
रं > ram/rang............rang/rambha
क्लीं > klim/kling............climb
हुं >hum/hung..............हु ( one doesn't hear
nasal in continuous speech)
मां > mam/mang..........prefer मॉ for teaching purpose
ह्लूं >hlum/hlung............ह्लू(one doesn't hear
nasal in continuous speech)
ह्लौं >hlaunm/hlaung......ह्लौ(one doesn't hear
nasal in continuous speech)