JSFiddle - React, Tailwind, and code Playground

JavaScript

function canBePalindrome(someStr) {
	var map = {};
    var arr = someStr.split('');
    
    arr.forEach(function(s) {
    	s in map ? map[s]++ : map[s] = 1;
    });
    
    var len = Object.keys(map).filter(function(o) {
    	return map[o] % 2;
    }).length;

	return arr.length % 2 ? len === 1 : len === 0;
}

console.log( canBePalindrome("mddm") ); // true
console.log( canBePalindrome("asiosaoi") ); // true
console.log( canBePalindrome("mdadm") ); // true
console.log( canBePalindrome("mdasdm") ); // false