ㄴ가 만나다

meet someone; sort of meet

The -ㄴ가 here belongs to a vague word, not to a verb ending. 누군가 만나면 is 'when you meet someone'. 뭔가 만나다 is looser — 뭔가 is doing filler work, so 뭔가 만날 일이 많이 없었던 느낌 is 'it felt like there wasn't much occasion to meet anyone'. After a time word, -인가 hedges the date: 작년인가 만나서, 'we met last year or thereabouts'.

Register: casual spoken