I came across a book Age of Bharata War by one, GC Agrawala. This is a sort of compilation of research papers talking about historic revisionism. Below is the synopsis of a chapter from it, clearly pointing out how confusing Indian history is.

Ancient Indian history is a chaos simply because everyone had their own eras – there was no standard which was followed. Saka era was followed till Gupta era followed it, Gupta was followed by something else. Very rarely, we see inscriptions, like the one at Aihole which gives us dates in more than one era. Because of this, though we know the date of an event in relation with everything, we don’t have an exact date simply because there is no anchor.

One of the main anchor is the Greek Synchronism theory forwarded by William Jones in 1793. Plutarch and Justin said that an Indian prince by name Sandrocottus met Alexander in 326 BC. They further go on to say that Sandrocottus rebelled against the existing order and established a dynasty ruling from Palibothra. Keeping in mind that the world started in 4004 BC, Sandrocottus was identified as Chandragupta Maurya and as he ascended the throne two years after Alexander left India, his ascent to throne was fixed as 323 BC. Puranas state Chandragupta ruled for 24 years, his son Bindusara for 24 years and Bindusara’s son Asoka ruled for 36 years.
Summing up, this gives us the dates as
Chandragupta Maurya 323-299 BC
Bindusara 299-274 BC
Asoka 274-238 BC

Buddha was a contemporary of Bindusara and Ajatashatru. Asoka became king 218 years after the death of Buddha. This puts Buddha’s year of death as 487. This gives the dates of rules for Ajatashatru as 495 BC. However, going by the Puranic tradition counting the succession of rulers, Ajatashatru is placed as 554 BC(ascended). This gives Buddha’s date as 544 BC. Now, working out the numbers back, it places Mahabharata at around 1400 BC. The link is Somadhi, the son of Sahadeva, the son of Jarasandha who died in Mahabharata.
Further corraborating this, Asoka’s rock edict 13 mentions some Yavana kings –
Antiyoka – Antiochus 265-246 BC
Turamaya – Ptolemy 285-247 BC
Antakini – Antigonus 278-239 BC
Maga – Maga of Cyrene
Alikasudara – Alexander of Epirus 272-253 BC or Alexander of Cornith 252-247 BC

Next is the Chinese link of Upali. Upali, a Buddhist teacher put a dot on the starting page of Vinaya Pitika every year. This tradition was continued first in India and then in China when the book was taken by one of his successors Sthavira. According to Buddhist tradition, this book was created when Buddha died. The practice of putting dots stopped during the rule of Loyang dynasty. The total dots was counted as 975 and by the time it was counted in 535 AD, it was 53 years since the last dot. This places Buddha again near 487 BC. Now the questions are these – what is an year? Gregorian? Indian? Chinese?. Next is, is there any guarantee that there were no years when the dots were not put? Next, is it possible that this is an invention by Sthavira to claim superiority in Buddhist echelons? Note that no one in China knows him and he left all his acquaintances back in India. Does this mean that, can this story be trusted?

Traditional Indian accounts place Mahabharata in 3102 BC but the analysis above places Mahabharata around 1400 BC. Supposing it is Chandragupta of the Gupta Empire and not Chandragupta of Maurya Empire who ascended the throne in 323 BC, it will push the dates by almost 1700 years putting Mahabharata around 3145 BC(300 years of Chaos between end of Andhras and Guptas, Andhras – 406, Kanva – 45, Sunga – 112, Maurya – 137, Nanda – 100, Sisunaga – 382, Pradyota – 138, Barhadratha – 1222).
Things in support of this proposition –
1. Asoka’s rock edicts name the Greek kings. While all other areas are represented by kingdoms in other edicts, is it correct to presume that only four or five are named after persons? However, there is no data available talking about these kingdoms elsewhere.
2. Asoka sent missionaries to all the parts of the world. But, there is no mention of a powerful monarch like Asoka in the chronicles of the kings mentioned. We should not forget that Asoka’s grandfather defeated another famous Greek, Seleucus and took his daughters as concubines. The nearest we get to is Diodottus – Devadatta.
3. Sandrocottus was followed by Amitrachades – Amitraghata. What is the basis to assume Bindusara is Amitraghata?
4. Satavahanas immediately adopted the Greek style of coins with portraits when they came across them. Is there any reason why Mauryans, who had such strong contacts didn’t use them, but continued with primitive punchmarked coins?

The author correctly points there is much to read not just in Indian literature, but in the history of every major entity from Sumeria to China to find out the real data regarding India.