Dear Nitesh,

With your point datasets, you may try using the Geostatistical Analyst tool for interpolation methods (IDW, Kriging etc.) for your study area. Yes, you can extrapolate the output raster to outside the given points.

Arun Kumar K C How can i extrapolate exaactly upto needed boundary?

Nitesh Bhandari Go to the "Layer properties" of the output raster - Extent - Set the extent to "your study area boundary"

See the R package gstat