Hi Amar,
You can add custom css in your datagrid cell based on condition.
For example , click the column header cell and go to appearance tab use dynamic cell section to add your custom CSS like below ,
if $currentobject/attribute>50
then
'color-red'
else
''
you can define the custom CSS with this class name called color-red
in your custom CSS file you can add below style
.color-red{
background-color : red;
}