Hey,
Here is the list of the most important topics of Chemistry(both 11th and 12th) :
Chemical Thermodynamics
Biomolecules and Polymers
Classification of Elements and Periodicity in Properties
Solid state
Metallurgy
Chemistry in Every day life
Atomic stricture
Chemical kinetics
Alcohol and ether
General organic Chemistry
P-block
Mole concept
Coordination compound
S block elements
Chemical bonding and molecular structure
Amines
Carbonyl compound
Carboxylic acid
Electrochemistry
Solutions
Haloarenes and haloalkenes
Chemical equilibrium
Isomerism
d and f block elements
See,Chemistry unlike others is an interconnected discipline you can't jump on a new topic without understanding the previous concepts. So,make sure your basics are strong.
Hope this helps.
Good luck.