new ssi unit

an ssi unit start production in oct. 2010,producing exciseble goods.up to 31-03-2011 turn over of unit is expeceted 70 lakh.

1.unit had to file any declaration in oct 2010 while starting production? or has to file any declaration on 01-04-2011.

2.if unit's turn over remain inbetween 90 lakhs to 150 lakhs in coming yaers, should unit has to file any declaration to ass.comm. on every 1st april.

thanks