Without trying to discourage you, from my view, every developer thinks that he or she is an architect or a designer. This is not a bad thing, but only a few really understand all the aspects of designing a complexsystem. This does not come easily. This does not come by preparing or sitting for an examination. The main ingredient is experience, but it is not the only ingredient. Just because someone has 6+ years of experience, he/she cannot be a good architect. Some do have real 6 years of experience whilst others have 2 years repeated 3 times.
So, to be a good architect, one should have experience, proven track record of designing software with the good understanding of the key areas, good engineering skills (analytical, problem solving, researching, methodical, etc), good soft skills like team work, commuincation skills, etc and personal attributes like being pro-active, positive, etc. This is not only true to become a good architect, but also to become a good calibre developer.
Writing and passing an exam has its purpose, but to be really successful in ones field, much more needs to be done. Writing an exam is just a start and one can make that start even without writing exams. So passing an exam is alone not going to cut it. One needs to have a proven track record of "successful application" of what he or she learnt in those exams. One can learn a lot "
if pro-active enough" on the job while gaining experience. While gaining experience, build the analytical mind to ask questions like
"Why should this be done this way?" , "Are there any alternative approaches this?" , "What if an exception is thrown here?", Is there a design
pattern to be used here? What is the best practice on this? and so on. Try to learn the theory or fundamental behind it and apply it in your regular work. Talk to your mentors about this and gain some insights.