My haemoglobin level is 7.6 and is there any problem?
Yes, 7.6 indicates you have anemia or any other blood disorder.
One way to increase hemoglobin content in the blood is to increase your iron intake. You can do this by eating foods rich in iron. These include spinach, liver and organ meat, cabbage, green beans, and tofu. Folate is a vitamin that your body uses to create haem and is present in spinach, rice, and meat. This way you can increase your hemoglobin levels quickly without medications.
Percentage of hemoglobin in RBC is around 34%. Generally in mammals the protein makes up about 96% of the red blood cells dry content, and around 34% of the total content.
For young males it is 14-18 g/dL or 8.7-11.2 mmol/L (SI units)