This chakra is located in the centre of the forehead above the eyebrows and is also referred to as "the third eye".
A balanced sixth chakra create a harmonious vision of reality and allows us to open up to the communication with a higher intelligence which brings clarity of thoughts and healing. When we can see clearly, we also have the ability to recognise patterns leading us to an insight in life were we experience an understanding of "the larger picture".
With an unbalanced sixth chakra we can experience difficulties to concentrate and have nightmares and headaches. It can lead to poor memory and vision, and also create a state of denial or difficulties to see the future or imagine what it could be.
To open the Ajna chakra we can practice Shambhavi Mudra, "Eyebrow centre gazing" and some types of pranayama which quites the mind and helps us draw our awareness inward. Finding balance between the chin and the hairline will also give your head a spacious feeling that allows the inspiration of the universe to flood.
Follow your intuition and seeking clarity and inner wisdom!