There are three types of solar setups 
1.Hybrid net metered (Takes additional units from grid when needed, and pumps back extra units if any to the grid)
2. Off Grid - With batteries . You use wapda at night/ or batteries depending on load. This system is not net metered. You use what you produce, charge batteries. At night use the batteries for lesser load or grid for acs etc. There is no exporting of units into the grid.
3. On grid system. This is a net metered system where electricity is produced by solar panels in sun time and extra energy is fed back into the lesco meter. You get credited for off peak units and your bill gets adjusted. If in 3 months you still have extra off peak units that you exported to LESCO, you get paid for it by check if you want or you can keep it with lesco for future adjustments. Peak units at 7 pm-11 pm and they are not adjusted or reverse metered.
Now what you are asking, is about hybrid system. If your hybrid is 10KW, it will usually allow you to connect 13 KW (13000 watts) of solar panels(Depends from inverter to inverter) Anything more than maximum allowed can cause damage to your system so never go above the inverter maximum panel wattage allowed.
SO lets says you have 10KW system. Your panels connected are of 13KW. Now this does not mean you will get 13KW, usually some energy is lost, efficiency issues, sunlight intensity, amount of light falling on panel etc. You will always produce below the 10KW inverter you got. This is just called over sizing on panels so that you give maximum productivity to inverter by installing maximum allowed panel wattage.
Now when your inverter will start producing electricity from the solar panels, you will not get consistent production throughout the day. There will be peak hour production where sun is more, light is falling properly on the angled panels etc. So your maximum production might be 7-8 KW on a 10KW system on a very bright sunny morning at peak times. Then it will go down as sun starts to set. so might go to 6 KW then 5 then 0 when no sun.
In cloudy days, rainy days when sunlight is less, you will need to shift to grid unless you have strong battery support. ACs cannot be run all night on batteries so people keep other load on batteries and acs on solar or grid.
In case you go for hybrid, and you are producing 8 KW on a 10KW system, and you need a total of 13 KW. then the inverter will pull in the 5 KW from gird. If you are producing 8KW but using 2KW. then the inverter will export 6 KW to Grid.
This is for hybrid inverter.
With on Grid net metered system (non hybrid) you will not have electricity due to any power outage in morning time if lesco is down. This system does not support battery. So if lesco is down at 1 pm, your inverter will be off too - no power. This is because in order for solar inverter to work, it needs reference voltage. When grid is out, it does not have reference voltage. In case of hybrid inverters - they have batteries connected so the battery provides reference voltage and then when lesco is out and the sun is shining, you are using solar directly and also charging batteries. TBH hybrid is not worth it.
Hybrid systems are maximum of 10KW and maybe 15KW if you can import yourself. This inverter is very expensive. if you need 20KW setup, you will have to use 2 units of 10kw hybrid inverter. You will also need to buy expensive batteries.
On grid inverter you can get 30KW inverter in price of one 10KW hybrid inverter. Plus you dont need to buy batteries. I would recommend go for On Grid net metered (NON HYBRID) if you are in dha and ry to get bigger capacity panels. If you use 10 KW, get a 15-20KW system so that you can have your bills zero-ed by producing extra energy.
