In the tv Judge Rinder show, who pays the amount granted as this is not a genuine law court, and how can they enforce it.?

The show's producers put up the money. Contracts are signed in advance. Contracts are enforceable.

TV court shows usually work like arbitration, all parties sign a contract agreeing to abide by the decision of the TV judge. The winning party could possibly end up having to sue to collect on the debt but that would eliminate any argument to weather or not the money is owed.

In a (real) court case, if you win, then the other party might (not) pay you. The hardest part of wining a case is collecting the debt.

Thus with the TV shows, both parties agree to be on the show, in exchange that the TV show (fund) pays if you win. Even the losing party gets paid a fee, just for being allowed to be on TV. They will also pay for the cost to get you there, be it by air as an example. They will pay for (1) night in a hotel plus dinner.

Years ago, about 20, my step daughter appeared on (??) Lake show. The episode was finding out that your BF was gay, which after 5 years came out. They paid for them to fly to NY or Chicago, the hotel and a dinner. To this day, they are still best friends and both have married to other people, him to his husband.

If it is the same as the old People's Court, the payment is made as part of the producers, in addition to the fees they receive for being on the show.

A law court is a building.
A Judge has the right to make a judgement anywhere, he is the law, not the building he is in.

In all such shows, the producer puts up yhe disputed amount. The person playing the judge decides how much goes to each party.

Before appearing on the show, BOTH parties sign a LEGALLY BINDING contract to accept the ruling as binding arbitration. Therefore the ruling IS legally enforceable.
Some of these shows actually make the payment as compensation for appearing on TV.

Usually there is a fund set by the show. They pay the judgment out of it, then split what ever is left.

I suspect the people who go on the show agree to abide by his decision. Although it is not a court of law, it CAN BE a valid legal arbitration, the terms of which can be enforced.