Answer: No it is not an integer
Any fraction like this is not an integer because integers are positive and negative whole numbers, including 0 also.
You can think of 3/5 as 0.6 after using long division or your calculator. Integers won't have any decimal portions to them.
The set of integers is {..., -3, -2, -1, 0, 1, 2, 3, ...}
Side note: 3/5 is a rational number since it is a ratio or fraction of two integers (3 and 5).