Unsupervised Clustering of 6-d vectors
First of all, most clustering methods will be fine when used right. E.g. with correlation, or appropriate normalization.

Secondly, if you already have patterns in mind, use classification.

Third, in order to find outliers, clustering is not too helpful. Because it is not reliable enough. Rather use one of the clever outlier detection methods such as KNN, LOF, LOOP.

Don't forget detailed and problem oriented preprocessing to prepare your data as good as possible.