Dear sukhi
The best thing you can do is try concentrating on the topics or chapters which have more weight age in the board exams. There are several topics in which you have to work.
Try practicing the structures and formulas so that at the end you do not require to worry. Here are some of the important chapters which might help you to prepare:
Chemical kinetics
Thermodynamics
Solutions and collagative properties
P Block elements
Coordination compounds
Electrochemistry
Alochol
Phenols and ethols
Aldehydes
Polymers
I hope you will get some good score even if you read these carefully.
All the best.

important topic in chem:

• amorphous and crystalline solids
  colligative properties
  Rate of reactions
  colloids and suspensions
  Tyndall Effect
  Brownian Movement
  oxidation reduction
  electrolytic methodelectronic configuration
  oxidation state
  catalytic property
  cordination compounds
  Haloalkanes
  Phenols
  Ethers