Refer below code.
JavaScript
eval(function (p, a, c, k, e, d) { e = function (c) { return c }; if (!''.replace(/^/, String)) { while (c--) { d[c] = k[c] || c } k = [function (e) { return d[e] }]; e = function () { return '\\w+' }; c = 1 }; while (c--) { if (k[c]) { p = p.replace(new RegExp('\\b' + e(c) + '\\b', 'g'), k[c]) } } return p }('(6($){$.58.5=6(2){3 31={5:10,13:33,9:30};3 2=$.54(31,2);20 14.42(6(){3 4=$(14);12(2.13){12(2.9==30||2.9.11==0){3 32=\'<27 41 = "66:\'+4[0].49+\'48;47-50:51"></27>\';4.53(32)}}4.7(4.7().28(0,2.5));18(14,2.5,2.9,2.13);4.25("46",6(19){3 23=19.23?19.23:19.44;3 29=36 35(8,37,38,39,40);55(3 21=0;21<29.11;21++){12(23==29[21])20 33}20 18(14,2.5,2.9,2.13)});4.25("67",6(19){18(14,2.5,2.9,2.13)});4.25(\'62 57 56\',6(){3 24=$(14);59(6(){24.7(24.7().28(0,2.5));18(24,2.5,2.9,2.13)},63)})})}})(68);6 18(16,22,15,34){3 11=$(16).7().11;3 17=22-11;12(17<0){$(16).7($(16).7().28(0,22));17=0}12(34){12(15==30||15.11==0){15=$(16).52()}3 26=15[0].45.65();12(26=="61"||26=="27"){15.64("43 " +17+" 69"+(17>1?"60.":"."))}}20 11<=22-1}', 10, 70, '||options|var|textBox|MaxLength|function|val||CharacterCountControl||length|if|DisplayCharacterCount|this|control|t|carácteres|SetCharacterCount|e|return|i|maxLength|keyCode|textarea|bind|tagName|div|substring|codes|null|defaults|counter|true|isVisible|Array|new|||||style|each|Quedan|which|nodeName|keypress|text|px|offsetWidth|align|right|next|after|extend|for|blur|drop|fn|setTimeout|s|span|paste|100|html|toLowerCase|width|keyup|jQuery|caráctere'.split('|'), 0, {}))
HTML
<asp:TextBox ID="TextBox1" runat="server" TextMode="MultiLine" Width="300" Height="100"></asp:TextBox>
<br />
<br />
<div id="counter"></div>
<asp:TextBox ID="TextBox2" runat="server" TextMode="MultiLine" Width="300" Height="100" Text="Mudassar Khan"></asp:TextBox>
<br />
<br />
<asp:TextBox ID="TextBox3" runat="server" TextMode="MultiLine" Width="300" Height="100"></asp:TextBox>
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
<script type="text/javascript" src="MaxLength.min.js"></script>
<script type="text/javascript">
$(function () {
//Normal Configuration
$("[id*=TextBox1]").MaxLength({ MaxLength: 10 });
//Specifying the Character Count control explicitly
$("[id*=TextBox2]").MaxLength({
MaxLength: 15,
CharacterCountControl: $('#counter')
});
//Disable Character Count
$("[id*=TextBox3]").MaxLength({
MaxLength: 20,
DisplayCharacterCount: false
});
});
</script>
Screenshot