If you finish Shemona Esreh ( by Mincha) and the minyan is up to Oleinu, and you have not said Tachnun yet, Do you say Oleinu with the minyan and then say Tachnun after Oleinu.
And once you have finished tachnun, should you say Oleinu again…since the first Oleinu was because the minyan is saying oleinu …so you join in.
Hope u understand the question 