I am sending data by using ajax call to 3rd party api to see if the card supports installment, then I get a response in the payment#new action, I just do not know how to show response on the view. 
ajax call;
                $.ajax({
                 type: "GET", 
                 url: "/payments/new", 
                 dataType: "json", 
                 data: {card_digit},
                 success: function(data) {}, 
                 error: function(jqXHR) {}
                }); 
payments#new action
def new
...
...
uri = URI.parse("https://...")
      https = Net::HTTP.new(uri.host,uri.port)
      https.use_ssl = true
      req = Net::HTTP::Post.new(uri.path, @headers)
      req.body = @body.to_json
      res = https.request(req)
      puts "Response #{res.code} #{res.message}: #{res.body}"
end
Then here it returns res.body as json object, I would like to show this on the view I have tried to assign to a variable like @return then use it on the view but no chance, I tried with respond to block but could not manage to do it either.
EDIT
Thank you for the answer!, 
But now I get error Encoding::UndefinedConversionError ("\xC4" from ASCII-8BIT to UTF-8) 
res.body returns;
{"bankId":"13","bankName":"...","cardFamilyId":"..","cardFamilyName":"...","cardThreeDSecureMandatory":"0","merchantThreeDSecureMandatory":"0","result":"1","serviceProvider":"2","supportsInstallment":"1","type":"1"}
I wrote;
render json: { res_body: res.body }
and 
console.log(data) in the success function
why would it happen?
EDIT
I added
render json: { res_body: JSON.parse(res.body) }