“At that time those who had come from captivity, the returned exiles, offered burnt offerings to the God of Israel, twelve bulls for all Israel, ninety-six rams, seventy-seven lambs, and as a sin offering twelve male goats. All this was a burnt offering to Yahweh. They also delivered the king’s commissions to the governors of the province Beyond the River. They supported the people and the house of God.”
This group then got together. They offered burnt offerings to God for their successful return to Jerusalem. This included 12 bulls, 96 rams, 77 lambs, and 12 goats. Notice the 12 bulls and 12 goats as a remembrance of the 12 now non-existant 12 tribes of Israel. This was a burnt offering. Notice the change from a first person narrative to a third person explanation. They also reported to the governors of the Province Beyond the River, which would have been in Samaria. Meanwhile they supported the people there and the Temple.