"What to do? SCJP/OCPJP 6 or 7?" If you are struggling with this confusion then do not worry, you are not alone. It is one of the most common confusion for any SCJP/OCPJP aspirant.
In our opinion, it is always better to learn the latest concepts. If you are a newbie in Java then our recommendation is that you go with OCPJP 7. This exam covers Java SE 7 features that will give you an edge over SCJP 6. Any potential employer will choose the most updated candidate provided the options.
Even if you are an experienced Java programmer, in that case also we recommend you to go for OCPJP 7. During OCPJP 7 exam preparation, you will understand the most recent features in the language that will improve your employability.
In fact, the OCPJP 7 exam is much more difficult to clear than its predecessor. This fact makes the OCPJP 7 exam more prestigious and more acceptable. Oracle clearly differentiated between the associate exam (OCAJP, the easier one) with OCPJP exam (definitely the difficult one) and hence the credibility earned by OCPJP 7 certification cannot be matched by the older certification.