Assalm-o-Aalaikum Some people say that "this name is heavy for the baby concerned" , is that islamic concept? Also some use numeology to choose the baby name (like there are many sites offering that) is that allowed in Islam?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.

We did not understood what you meant by 'some names are heavy on the child'. If you meant that they are difficult for children to pronounce, then it is known that a child may find it difficult to pronounce some words, and he may say some words that are not understandable at his early ages, as his vocal cords and articulating limbs are not yet fully developed.

As regards relying on numerology in naming children, then what we know is that this act is linked to fortune-telling as one uses the numbers in calculating the future of the person and try to guess what will happen to him in the future. This method claims that every letter corresponds to a number, and every number has a certain indication, and there is no doubt that this is soothsaying and fortune-telling, and both are forbidden and may lead to disbelief and take a person out of the fold of Islam.

For more benefit, please refer to Fataawa 82923 and 85039.