Tax on SIP investments

As per IT Act, tax on Long term capital gains is NIL. A capital gain is termed log term if the asset is held for more than a year. However when Mutual Fund SIP payments are done on a monthly basis, say Rs.1000 per month for 12 months, accruing say, 250 units of the scheme and the investor wishes to sell 100 units of this in the 14th month from the date the SIP was stared, then how do the capital gains termed as? Is this Long Term or Short term?