I think its a female berg pin. I have a requirement of a similar part But I am not able to find it. What is it called?
Those are machine tooled single inline sockets.
Different manufacturers use slightly different terms. Note that the ones you show were cut from longer strips, which is why the ends are all ragged.
A couple of generic descriptions via Digikey:
Mill-Max: "Connector Receptacle x Position 0.100" (2.54mm) Gold Through Hole" Preci-Dip: "Connector Socket x Position 0.100" (2.54mm) Gold Through Hole"
There are also similar parts with stamped contacts rather than the (relatively expensive) screw machine parts ('turned', 'machined') that are in your photo. The height above the board varies as well as the number of pins.
That is a breakaway female header strip with machined sockets and solder tails. You can find them at certain distributors such as Digikey. Also look on eBay for lower prices with correspondingly lower quality.
Manufacturers to look for include MillMax and Samtec.