I would like to know what can make you fail a top security clearance? Like would it matter if relative like uncles r father had problem with the law or does it only matter if your record is clean?

It's unlikely the any relatives having general issues with the law are going to influence your security clearance.

My husband and I both have Uncles who have had issues with the law and it does not effect his security clearance.

Basically they are looking at your background for the past 7 years. Some of things that might affect you, jail, drugs, and the biggest finance. The best bet if you think there might be a problem you should talk to the a security mgr.