Poor Munna! It sounds like he's frightened and uncomfortable about being bathed, which is a common problem in dogs - this often causes struggling, growling, and biting since this is the only way that he can tell you he's afraid. You can work with him to help make him more comfortable about getting baths by using lots of treats and praise, and going very slowly.
For example, you might start by putting a handful of treats in the empty bathtub, or smearing some peanut butter or spray cheese along the side of the tub - let him decide to get in and eat them at his own pace. Do this for several sessions, until he is jumping happily into the tub as soon as you get out the treats. At that point, you can run a small amount of water (just an inch or two) in the tub while praising and giving lots of treats - then let him out. Repeat this until he's comfortable, etc.
Gradually work up to being able to give him a full bath - use peanut butter or other treats so that he can be eating the entire time, and stop if he becomes upset. With time and patience, all dogs can learn to tolerate and even enjoy bathtime - so it's definitely worth working on :)