Ms.Sujatha, I'm going to try to explain a bit about the process, if it is incorrect please feel free to write the correct version. :)
I've seen this type of work done in our local craft store (Michael's). It is basically the criss-cross technique, where we arrange one set of ribbons vertically, close to each other, and stitch the bottom ends to keep in place. The horizontal lines are done, one ribbon at a time, weaving it under the first vertical ribbon, over the second vertical ribbon, under the third one, and so on and so forth, in an alternate fashion. After the entire area is completed, the finishing edges are secured by stitching it. Usually in this type of cushions, you'll see ribbons like these woven on one side, and plain matching cloth-material on the other side.
Thank you for sharing this beautiful work of art, and for mentioning where you got the materials from. It helps! :)
In reply to where do u get satin ribbons by Sumathi.v
In reply to sumathiji I got those by sujatha_123