Babies have the ability to hold onto things that are placed in their grip from birth, but around 3-6 months this movement becomes more planned and intentional rather than a reflex. Their brains are working really hard to organise the coordination of thought, intention and physical movement. When babies are lying on their tummies and have good head control, they are then able to develop a sense of balance which allows them to reach by moving their arms independently at first and then together.
There are some great toys, which you could use with your baby to encourage reaching and grasping skills such as rattles, loopy links and musical car keys. Although, babies prefer moving objects to static ones, don’t keep shaking toys too frantically at them, hold them still long enough to give your child time to focus on it. Then move it from side to side, try up and down, close and a little further away to encourage stretching and grasping. .