Answer
8 electrons for n = 2
4 electrons for ms = +1/2
Explanation
The principal quantum number, n = 2 implies the electrons are in second energy level. There can be a maximum of 8 electrons for n = 2. The 2s subshell can hold 2 electrons, and the 2p can hold 6 electrons.
Since there are maximum of 8 electrons for n = 2, then maximum of 4 electrons will spin-up (ms = +1/2), and maximum of 4 electrons will spin-down (ms = -1/2)