What is the name of the knit stitch on these given pictures?
That sweater is probably made on a knitting machine, but you can reproduce the look on knitting needles. It looks like either fisherman's rib or brioche stitch, with added tuck stitches every 3 or 4 rows. To make a tuck stitch, instead of knitting into the next live stitch, you knit into that stitch and the stitch below it.
Brioche and tuck stitches are a broad category including many stitch patterns. You can find knitting patterns with these stitches on Ravelry with the search filter Attributes: Fabric Characteristics - brioche / tuck stitch.