Vyasa's Mahabartha was composed as Kakawin Bhāratayuddha in the 11th century under the patronage of King Dharmawangsa.
Bhisma's visit to the Kingdom of Kashi:
King Shantanu and Satyavati sends Bhisma to join the swayamvara in Kasi to win the three princesses Amba, Ambika and Ambalika for his two younger brothers, Chitrangada and Vichitravirya. In the Indian version, Shantanu and Chitrangada are already dead.
Amba falls in love with Bhisma and wants to marry him. Bhisma tries hard to convince her of the promise that he undertook. He asks Amba to marry with her lover, Salwa, the King of Soba Kingdom. But she has already admitted Bhisma as her husband. Bhisma tries to scare her with his arrow.Unintentionally the arrow gets shot, and Amba is killed. Amba's spirit curses Bhisma that in Barata Yudha(i.e. Kurukshetra war) she would pick-up his soul through a lady-warrior expert in archery. Bhisma deeply regrets the accident because he has also started loving Amba. After his death in Barata yudha, his soul and Amba's, live together happily in eternal life in heaven. There is no Bhisma-Parashuram duel here or Amba's reincarnation.
Draupadi's Swamvara: Here there is no archery competition. The winner of the contest is to be the one, who can defeat, Patih Gandamana, uncle of Draupadi,( a character introduced in Indonesian version) in a duel battle.Meanwhile, Kunti and Pandavas decide to join the contest, with the purpose to get a wife for Yudhishthira. As Bhima is already a married man, he represents Yudhishthira and defeats Gandamana and wins her for his elder brother. Gandamana knows of his imminent death and gives his strength to Bhima before his death. That it is Bhima and not Arjuna who wins Draupadi.
Karna-Arjuna meeting: The most touching and tearful moment in the Indonesian version is the Karna-Arjuna meeting on the eve of Karna's first day as the commander in chief of Kaurava army's. Arjuna secretly visits him. He has the most difficult moment in his life. Arjuna suddenly stands in front of him, kneels and greets him respectfully and says clearly, 'Please accept my sincere respects and Pandava's respect to you.' Karna is deeply moved. His eyes are filled with tears. Arjuna proposes to make him the emperor of Hastinapura and hopes that he will join them. They speak emotionally with each other and express love for each other. Finally, they decide to adhere to their Kshatriya duties and fight in next day's battle. Then they embrace each other again without a word and Arjuna leaves with Karna's permission.
Next day after Karna kills Ghatothkacha; Karna's chariot is scattered to pieces when Ghatothkacha's body falls from the sky.With no chariot, he meets Arjuna directly. He is aware that Arjuna calibre. But he is happy to be killed by a mighty, powerful brother.Finally, Arjuna releases his Pasupati arrow piercing Karna through the neck. Karna's death is mourned deeply by both sides. The Pandava family performs Karna's funeral rites with full honor.In the Indian version, Karna is beheaded.It is only at the end of the war after Kunti reveals Karnas' identity to the Pandavas.
This only a smaller portion of the variation in Indonesian Mahabartha.There are many of them.The following link can provide you with more information and comparison in great detail. Variations in Indonesian Mahabharata
The Regional versionssection of Wikipedia page provides with some variation between Vyasa and Indonesian Mahabartha