Hi Anoop,
After 12 months of SIP can i redeem it any time?
Yes you can redeem any time (but not in case if you invested in ELSS or Pension Plan)
Can i extend the SIP period?
Yes, but for that need to fill sip auto debit renewal form to continue sip.
If i extend when can i redeem the amount i paid for 12 months? is it only possible to redeem the entire amount after completion of the Extended SIP period?
Extension of sip is nothing to do with redemption, you can redeem very next day after you purchase,
only problem you will pay exit load if applicable for that scheme you invested.
If i purchase some more units of the Same fund, will it be treated as a new Folio?
No, if you buy the units by transaction slip of same folio or when buying and using common application form but mention the folio, purchase will be added in existing folio
when treated in new folio
when you purchase using application form and don't mention your old folio number.