This thread is to understand the world of Mahabharata and how they differ from each other. I am not going to certify which is original and authentic but obviously I want to make sure the source of different stories and why not every thing can be attributed to Veda Vyas.

There are three types of Work available on Mahabharata -
1. Sanskrit Unabridged Mahabharata (And it's translation in different languages) - Generally this work is attributed to VedaVyas

2. 2. Vernacular Mahabharata written in regional Language - There are regional poets who rendered Mahabharata in regional vernacular language and they took their own creative liberty and therefore each one some times different than others.

Example -
Oriya - Sarala Dasa, 15th CE
Malayalam - Bharatam Pattu Ayyanappilla Asan commentary by P.K. Narayana Pillai, National Book Stall, Kottayam (1988).
Bharatamala Niranatt Sankara Panikkar (15TH CE)

With study and commentary by Dr. Ponnara Saraswati
published by Kannassa Smaraka Trust, Niranam, Tiruvalla. (2003).
Bharatam Niranatt Rama Panikkar (15th CE)
Cherussery Bharatam Cherusseri Namboodiri (15th CE)
Sri Mahabharatam Kilippaattu Tunchattu Ramanujan Ezutthachan,(16th CE

Bengali - Kabi Sanjay, (First half of 16th CE - the oldest Bengali Mahabharata)
Kasiram Das, (1650)
Tamil - Perum Devanar, eighth century
Vhilli Bharatam(15th CE)
Kannada - Pampabharata, (902)
Kumara Vyasa , (1494 - 1520)

Telegu - The Telugu version of Mahabharatha written by Kavitrayam (Trinity of poets), consisting of Nannayya, Thikkana and Yerrapragada (also Known as Errana).The three poets translated the Mahabharata from Sanskrit into Telugu over the period of 11-14th CE

So there could be some stories which are not present in Sanskrit Mahabharata and some stories which could be different than what is available in Sanskrit Mahabharata.

Now coming to Sanskrit Versions - there are ample manuscripts of Sanskrit Mahabharata present in different scripts such as Sharada, Devanagari, Maithilli, Bengali, Nepali, Grantha (Telegu), Tamil, Malayalam. They are written in Sanskrit language and but in different scripts.

So based on scripts there are two major divisions of Mahabharata -
1. Northern Recension - Manuscripts / editions based on Sharada, Devanagari, Nepali, Bengali etc.
2. Southern Recension - Manuscripts / editions based on Tamil, Grantha or Malayalam (To be continued)