1) I am in IT profession, presently working in GE Energy India. I am planning to apply for the Tier1 Visa in UK. But prior to that I need to ascertain whether my parents can stay with me in UK if the Tier 1 Visa is granted to me. I am married & have a 8 years old son.

2) What is the health insurance policy in that case.

"Dependents" mean spouse, sons, daughters ONLY. Not parents, uncles, aunts, brothers, sisters, etc.