$str = "<tr><td width="0" align="center"><font face="Arial" size="2">5 Digits </font></td>";
if ($str =~ m/(<[Tt][Rr].*>)/ ) {     # using .*
    print $1, "\n";
}
# or 
$str = "<tr><td width="0" align="center"><font face="Arial" size="2">5 Digits </font></td>";
if ($str =~ m/(<[Tt][Rr].*?>)/ ) {    # using .*?
    print $1, "\n";
}