According to Osho, 'constitution' means an individual's psycho-physical makeup—the designed structure of a being—whereas 'prakriti' is utterly different: the primordial, uncreated, beginningless nature or material that precedes and underlies all creation. Srishti is what is made; pralaya is dissolution. Like a house, the plan is constitution; the earth, air, and heat it’s built from are prakriti. No exact European equivalent exists.
No: constitution is your body-and-mind’s design, while prakriti is the timeless stuff everything comes from, existing even before anything was made.