In Mexico "ni modo" means "it doesn't matter", "whatever", "not important", "oh well", "no big deal" and quite a few more things, just depends on the context.
"Si quieres manejar,pues maneja, si no, pues ni modo" > "If you want to
drive, drive but if not,whatever no big deal"
"¡Se cayó el huevo! Ni modo, hay mas." > "The egg fell. Oh
well/doesn't matter, there are more."
"Mi cel no funciona aquí, ni modo, ¡el tuyo sí!" > "My cell doesn't
work here, no big deal, yours does."
"Creo que ella está enamorada de ti." "Ni modo." > "I think she's in
love with you." "Whatever."