CIN Querries !!!!!!!!!!!!!

Dear Experts,

Can you please explain follwing querries regarding CIN

1) J1ID - Material & Chapter ID Combination - GR/IR X ref field - with significance and which option is preferable at what scenario?

2) for what Input material and output material is maintained for plant in CENVAT determination. and why we maintain ouyput material same as input material.

3) While creating condition record in FV11,

which combination is functionaly prefered ? (Material/Vendor /plant)

4) What is Tax Classification (condition record) ?

Please answer, its very urgent

Thanks and regards,