In fission process the organism simply divides or splits into two or more equal sized parts, each other later becomes a complete organism. Is it necessary that it will divide into equal sized daughter cells?

Binary fission is a form of asexual reproduction, which is common among bacteria. In this type of reproduction, a single parent cell divides into two and forms two daughter cells, which will be replicas of the parent i.e they are genetically identical to the parent cell and nearly in shape and size also. But since mutation can occur during cell division, they may be slightly different.