मुझे तुमसे बात नहीं करनी
And
मुझे तुमसे बात नहीं करनी है
Both are same and, In hindi, now a days sometime people don't use " hai (है)" in many places.. Because the meaning of the sentence does not change,
Example-
तुमने बहुत अच्छा गाना गाया है|
तुमने बहुत अच्छा गाना गाया |
But we can't do this to all the sentences, only few sentences are there in which you do this ( removing हैं, हूं, थी, था etc)
Example -
पानी बहुत गरम है
पानी बहुत गरम
Here second sentence is not clear so it is wrong here to remove* है *