Did nebuchadnezzar go to heaven

No. There is only a specific number of people going to Heaven-144,000. These individuals are handpicked by Jehovah God and Jesus, and they lived a life being faithful to Jehovah clear to the point of death. (Revelation 14:1-4) Nebuchadnezzar didn't live his life in such a manner.

However, if on his deathbed he did accept Jehovah's ways, he'd be part of the group of "righteous" ones that will be brought back to life in the future on Earth. (Acts 24:15; John 5:28-29)

(New World Translation of the Holy Scriptures)