Do we have Double in Oracle?

Yes, Use this:

number(p,s)

Where p is the precision and s is the scale.

For example, number(7,2) is a number that has 5 digits before the decimal and 2 digits after the decimal.

alter table
_TABLE_NAME_
modify
(
VAR_LIMIT NUMBER(38,127),
EAR_LIMIT NUMBER(38,127)
);