How to get a medical support for my parents?

They are entitled to nothing.
The NHS is cracking down.

http://www.telegraph.co.uk/news/2016/10 … m-foreign/

Agree with the above.  Increasingly proof of permanent residency/citizenship is asked for by NHS hospitals/treatment centres.  There have been increasing numbers of cases where foreigners, who have not contributed to the UK National Insurance scheme, seek medical attention from the NHS (free at the point of delivery). 

Charges are being applied (as per the article attached above), as the NHS struggles to cope with the financial demands of treating the UK population.  Having said that, the NHS will treat medical emergencies, no matter where the person is from.

If you bring your parents, they will not be given age related priority for anything and in fact it is likely to be very difficult to register them with a doctor and you may have to resort to private medical care, which is extremely costly in the UK.

ok thanks, I also want to ask if there is a Health insurance for a expat like me and for my parents also?

thank you,

You can look for an expat health insurance company. The company I work for is based in London and is made up of many expats themselves. I don't know if I am able to post the link to them through am I?