If any activity can be developed into a system with a clear method producing predictable and consistent results, it is a Science.
Guys...get used to it!
Unfortunately for you, Sriram, your persistent misuse of the word in its modern meaning rather backfires on you. In seeking to imply that Spirituality is an activity that " can be developed into a system with a clear method producing predictable and consistent results" you are faced with the anomaly that
all religious systems fail to produce 'predictable' results. Yoga etc certainly can produce a change in consciousness, as can the spiritual exercises of St Ignatius or St John of the Cross. But there's no provable consistency, any more than drinking many pints of alcohol will produce a provable consistency of effect in most people who drink such amounts - not even to the point of being completely drunk. Many effects could be observed, including extreme vomiting. There are a likely to be changes of consciousness, but not predictable ones.
There is a discipline to correlate such mental and physical states: it is called
phenomenology, and that falls short of being a science.
Your reason for trying to foist this archaic and vacuous meaning on the word science is, I suspect, rather akin to that of biblical fundamentalists, and their talk of "Creation Science". They realise they live in a culture where scientific enquiry in the true modern sense is a dominating and respected feature of modern life, and wish to claim the word 'Science' for themselves, in a spurious attempt to gain respectability for their cranky ideas - to be more 'scientific' than the scientists themselves. However, the modern discipline of science was simply a development of what was previously called
natural philosophy, and that had a specific aim and scope. Science asserts a certain kind of authority: here is a systematic approach which will reliably advance our understanding of the natural world. But the knowledge is always provisional: every idea, every assumption is subject to challenge, to question and possible refutatation.