First, identify the molecule:

Highlight the parent compound in red
Highlight the methyl substituents in blue

The molecule is 2,3-dimethylpentane

Carbons #1, #5, and the methyl substituents are not chiral because they are each bonded to three identical hydrogens.
Carbon #2 is not chiral because it is bonded to two identical methyl groups.
Carbon #4 is not chiral because it is bonded to two identical hydrogens.
Carbon #3 is chiral because it is bonded to four different groups:

an isopropyl group,
an ethyl group,
a methyl group,
and a hydrogen.

The isopropyl group has the highest priority,
he ethyl group is second,
the methyl group is third,
and the hydrogen is forth.
Rotate the lowest priority (hydrogen) away from you.
Spinning  #1 to #2 to #3 is to the right so it is in the R configuration.