0k, here are my answers:
1. Gnostics. They claim a billion things, but they are divided and have many different beliefs that have nothing to do with the original scriptures. Their origins are based on greek philosophy and oriental mystical beliefs, which is already an indication that it is not from the original scriptures. Many of their beliefs are so contradictory to the Bible. Let me give you a few examples:
a. They believe in the "Gospel of James". This book says that Mary was a perpetual virgin before and after the birth of Jesus Christ. Yet, clearly this is a lie because the Bible clearly says:
Matthew 1:24, 25
24 Then Joseph woke up from his sleep and did as the angel of Jehovah* had directed him, and he took his wife home. 25 But he did not have sexual relations with her until she gave birth to a son,+ and he named him Jesus.+
(note, if Jesus had brothers and sisters, then Mary was not a virgin anymore because she clearly had sexual relations with Joseph).Matthew 13:55, 56
55 Is this not the carpenter’s son?+ Is not his mother called Mary, and his brothers James and Joseph and Simon and Judas?+ 56 And his sisters, are they not all with us? Where, then, did he get all of this?”+
b. Gospel of Thomas is also used by the Gnostics. This book talks about Jesus as a child and using his powers for revenge to hurt people. In some cases Jesus supposedly blinds neighbors and also kills people.
c. Gospel of Judas, also used by the Gnostics. It says that Judas was a hero when the original scriptures put him as a traitor. Plus, it wasn't written by Judas, and it was written centuries after Judas (in other words, something made up). A scholar in early christianity called Bart Ehrman said about this book:
It is not a Gospel written in Judas’s own time by someone who actually knew him
So, just a real quick study of what the content is about, in about 1 hour, I could easily see that they are not part of the original scriptures. Either someone believes in the Bible, or believes in these. A christian cannot believe in both because they are contradictory. Not only are these books teaching something completely different from the Bible, but some like the Gospel of Judas, are not even from Jesus times. As I said before, a context and historical study of these texts already bring out the manipulations of the original text. This is why biblical scholars do not add these books to the Bible.
2. I have not found any evidence that Jesus was in India. Those are all theories, not evidence.