It's Adiantum incisum - also grows on walls in Kathmandu. A "walking fern" because the little bulbils at the tips of some of the leaves grow new plants when the leaf-tip touches the ground. I've seen four "generations" of vegetatively extended plants on one original leaf, even, hanging down a wall!
I have the African equivalent growing in my little fern-garden here in Portugal, but they are different taxa and I wish I had this one, but it didn't survive the plane-journey in bags! This one is subsp. indicum, a diploid.
Best wishes,
Chris.