>In this context how does the Heisenberg Uncertanity Principle

Physics is the discipline that uses mathematical models, called Physics Theories, to describe observations and data, and, **very important** to predict future behavior. (A model that only fits existing data is a map, not a theory). So quantum mechanics,  the theory developed from observations and measurements, has introduced indeterminacy because it is necessary to describe the data.

It was found that the differential equations that describe wave functions can be used to model the observations and data, if extra axioms pick up the correct solutions that can be descriptive and predictive of data. Principles, laws, [postulates][1] are the names used for these axiomatical statements. The Heisenberg Uncertainty Principle (HUP) was  deduced from  data that were incompatible with the microscopic world, where mostly the new quantum theory is needed, can be shown to emerge from the commutation relations of the complicated theory of Quantum Mechanics. 


> bring about the notion of so called indeterminism ,in the sense that how do we know it is a fundamental law of nature

In the final theory, the indeterminacy comes from the wavefunction postulate

  $Ψ(x,t)$ = single valued probability amplitude at $(x,t)$

  $Ψ^*(x,t)Ψ(x,t)$ = the probability of finding the particle at $x$ at time $t$ provided
                      the wave function is normalized

This is what makes for the basic indeterminacy in quantum mechanics, and the theory was developed in order to explain the data of that time: photoelectric effect, black body radiation, spectra of atoms. It prevailed because it was **predictive** of new data.


> that doesn't allow us to make some observations and unlike the average Newtonian chaotic system (turbulent flow of fluids and the like) which is labelled deterministic chaos.

The concept of probability in both classical mechanics and quantum mechanics is the same, the same with the simple probabilities of throwing a dice.

In classical deterministic chaos dealing with the many particle states, it is the complexity of the enormous number of particles that displays an emerging chaotic behavior, inability to exactly determine individual particle tracks. Quantum mechanics, by identifying particles with a probability distribution are inherently non deterministic. There are theoretical efforts to define an underlying deterministic layer of physical quantities from which the indeterminacy of quantum mechanics emerges, but they are not successful up to now,  that is another long story.

  [1]: http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/qm.html