으려고 해도 is a combination of two patterns (으)려고 하다 and 어/아도. (으)려고 하다 means "to be intending on something, to be planning to do something" ex) 친구가 이사하려고 해요. My friend is planning to move. 어/아도 means "even if, even though" ex) 요즘에 바빠도, 운동은 하고 있어요. Even though I’m busy these days, I’m still doing some exercise. (으)려고 해도 means "Even though someone is trying to do something" 왔던 곳으로 되돌아가려고 해도 날이 어두워져 길이 잘 보이지 않는다. Even though I am trying to return to where I came from, I cannot see the road clearly because it has gotten dark.