How formation of Dalta-Bond rake place and by which orbitals?

@ pranav 
the delta bond are covalent chemical bond , 
where four lobe of one involved atomic orbital overlap with four lobe of other involved atomic orbital . 
the overlap leads to formation of bonding molecular orbital with two nodal planes which contain the internuclear axis and go through both axis . 
it is formed generally by overlapping of two d orbitals . 
HOPE IT CLEARS YOUR DOUBT 
all the best