Let 2 be fixed at unit's place.The ten's place can be filled up in 6 ways.The hundred is place can be also be filled in 6 ways.
No of numbers that can be formed when 2 is at unit's place=$6\times 6=36$
Similarly when 4 is at unit's place,the number of numbers that can be formed =36
Again when 6 is at the unit's place.The number of numbers that can be formed =36
$\therefore$ The total numbers of ways when 3 digits numbers can be formed,the digits being repeated =$36\times 3=108$
Hence (C) is the correct answer.