when I accelerate my car gear makes sound 'ka' each time it changes from one gear to another.
Check your transmission oil level. Pull the stick when the engine is running and tranny is warmed up. Hopefully, all it needs is some oil. If oil is full, and you have no visible leaks, then I would bring it into the shop. Once an auto transmission starts to make noise and klunk, it's about ready to go........you may want to check under the hood and look at your motor mounts. If one or more is broken, every time you give your car some gas, the engine wants to naturally "twist". If your mount is broken, it could just be your engine knocking into something like the frame.
Don't know if you have solved the problem yet or not but if your model has an ECT button, it may be on. Try switching it to off. That button will make the tranny shift differently.
Search Toyota Camry Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Toyota Camry Experts