Will practising ncert oraganic conversions be …

Stick to NCERT for everything. Physical is easy, practice numericals (specially NCERT questions)  learn definitions and the read NCERT word to word.
Organic, something people fear. Don't fear it. Make a list of all the important reactions you come across and revise them daily! Names of the compounds, reagents and everything. Learn them by heart. Practice as many questions as you can. Refer to previous year and sample paper questions. Redo them until you're absolutely sure of them. Understand and then learn, will benefit you a lot. Make sure you know all the name reactions, it'll fetch you 3-4 marks easily. Make sure that you do all the NCERT questions thoroughly, be it examples or back exercise questions.
Chemistry exam is usually simple and direct. So don't worry much. 
Don't miss the last chapters, they are very scoring if done properly.
And pdf blocks. Do NCERT religiously! Every line is important. Try to answer all questions in the language used in NCERT, specially for reasoning questions.