Depends in which part of north east you want to visit if you are visiting meghalaya it should be okay. but if you are visiting arunachal sela pass gets closed sometimes due to snow. .
Apart from Arunachal, rest of the states can be visited. Passes in Arunachal depend on the weather. Also, keep in mind that in order to visit Nagaland, Mizoram and Arunachal you need to get an inner line permit. The best season to visit NE is October to March so rest is sorted.