You don't mention what field you're in or what country you want to apply to, but let me answer for computer science in the US.
Is the evaluation of research statement done differently for professional masters and research masters? If so, what are these differences.
Professional masters programs won't ask for a research statement at all.
There are two types of computer science masters degrees in the US. One is the research masters, which requires a thesis in addition to advanced coursework. The other is the professional masters, which is entirely based on coursework, with no research component. Research masters students generally work with faculty advisors on a research project and may even be funded by teaching or research assistantships that include a tuition waiver. Professional masters students pay full tuition (or get their employers to pay for them), and take classes and nothing else.
can I take admission into professional degree first and then make a transition to research degree in order to increase my odds of admission?
In my experience, absolutely not!
Professional masters degrees are considered to be terminal degrees. Because they lack a research component, they are not considered pathways to a research degree.
I am an international applicant applying to US. So I do not with to go for PhD directly.
Why not? At least in my department, a strong majority of PhD students are international, and most of them apply as undergraduates. And I don't think my department is special in that regard.