What are the necessary(must) conditions for stability in z domain? I am sure about one(ROC must include unit circle) Is there any other such condition which states that there shouldn't be any poles in ROC?
The one and only condition for BIBO stability of a 1D discrete-time system, in the z-domain, is that its transfer functions's ROC (region of convergence) should include the unit circle : $|z| =1$. Therefore, it's a necessary and sufficient condition for BIBO stability of a 1D SISO system.
There are no other conditions (to my knowledge).
EDIT [based on comments] : By definition of ROC (region of convergence) there cannot be any poles inside the ROC region. This's related not with stability but with convergence. And also, causality is not related with stability too.
Properties of ROC is a different question to be answered.
Here is one viewpoint in evaluating system stability.
 System z-plane pole(s) lie outside the unit circle: System impulse response increases, with time, toward ±infinity. System frequency response does not exist. System is unstable.
 System z-plane pole(s) lie on the unit circle: System impulse response remains non-zero and finite for all time. System frequency response exists but contains infinite-magnitude value(s). System is conditionally stable.
 System z-plane pole(s) lie inside the unit circle: System impulse response decreases, with time, toward zero. System frequency response exists and contains no infinite-magnitude value(s). System is stable.
ROC cant include poles because the impulse response wont converge if it includes poles and hence the system will be unstable. Also, the ROC must include the unit circle because if it includes the unit circle, the Fourier transform is defined since the unit circle represents convergence of FFT.