Hello....
Why Complementary Feeding?
1.     To give extra nutrient to the baby because the breast milk become inadequate, according to 
        his nutrient demand
2.     To teach him to swallow solids. Start with dilute semisolid, and gradually increase the thickness 
         every week, and slowly go on solid.   
When to start weaning:
1.     After 6 month, breast milk is definitely inadequate.
2.     After 6 month intestinal 
amylase levels are adequate .and gut mucosal integrity is satisfactory. 
General Principal: 
1.     Since the child moves the tongue as though for sucking, it is but natural that some of the 
        semisolid given will be coming of the mouth. It is not spitting or rejection of food.
2.     Since the baby is used to the taste of milk alone, it is better accepted if the weaning food is 
         mixed with milk.
3.     He should encourage to feed, but should never be forced, as this creates an aversion to 
        feeding.
4.     Give small quantity of food, gradually increased as per demand.
5.     If he rejects any food item, it should be stopped, and may be reintroduce a week or two later. 
6.     It is preferable to introduce only one new food a week, so that intolerance can be spotted.
Preparation and Storage of weaning food: 
1.     Careful hygienic preparation and storage of weaning food to prevent contamination.
2.     Before preparation and weaning hand should be washed with soap.
3.     Cooking place and utensils must be clean. 
4.     The food preferably fresh, cooked or boiled well and if feasible, prepared immediately before    
         the are to be eaten. 
MY OPINION IS:
If mother having adequate breast milk, which satisfactory to your child,
Child have gaining weight as expected age.
Then you can wait for 2 month more for weaning.  
Still you have to start weaning :
Continue Breast milk,
introduce vegetable soup, 
fruit juice, 
dal water 
Single cereal (Ragi, Rice, Suji etc),Coconut milk,  
Thanks 
Regards Dr. Sagar Mhatre