Carrie5 on Family Tree Circles

I am interested to find out anything about my grandfathers history. He was born in Scotland, had many brothers and sisters, but lived in Dublin. All of his siblings were born in Glasgow, and then lived in Dublin, I think. Some of his family is not listed on Ancestry.com and I don't know why. It should be public info to find out about your own roots? Doesn't seem so. His mother was Catherine Mc. Pherson, Scottish and Richard Jago, Irish.