How do i fill up the space marked in the attached image?

Bounded plane doesn't work as its on different plane. I'm trying to do a cap.

3 Answers

Try an n-sided surface. Line selection set to, 'stop at intersection'. This is plan A.

There is usually a boundary patch option in most softwares. I'd give that a shot to start.

Try to use Fill command in surface ribbon tab. If results are not satisfied.

Go further the studio surface in surface ribbon tab. This time you definitely like it.