R = (1 + r/100) where r is rate of interest divided by number of installments in the period of interest.
P = Principal or Loan Amount.
n = Total number of installments one has to make.
EMI = Equated monthly installment.
Then for a simple case of three installments,
((PR - EMI)R - EMI)R - EMI = 0
PR3 = EMI * (1 + R + R2)
Without any loss of generality,
PRn = EMI * (1 + R + R2 +... + Rn-1).
EMI = PRn(R-1)/(Rn-1)
EMI = P*r/100*(1 + r/100)n/((1 + r/100)n - 1)
Thus, if loan amount is 10,00,000 for 5 years @ 6% (half yearly), installments being paid every month then,
P = 10,00,000
r = 6/6 = 1. (Six installments being paid in half year.)
n = 12*5 = 60 installments.
So, EMI = 10,00,000 * 0.01 * 1.0160/(1.0160 - 1) = Rs 22,244.
I hope this helps...