As of 5 o'clock, the ruling party has secured 50 seats.

Literal

Ruling-party [topic-は] 5-o'clock present [at-で] 50-seats securing-is.

~現在 ('as of') is a set phrase for reporting data at a specific time. 議席 ('legislative seat') is the counter/noun for parliament seats. 確保する ('to secure / ensure'). Election-night reporting register.