1) I presume that you have purchased shop by registered sale deed being executed in your favour by the service society
2) I presume sale deed was executed by second partner on basis of valid POA being executed by first partner
3) if said POA is forged and first partner has moved court then all transactions entered into would be called in question
4) you can sell your shop if you have clear and marketable title to shop
5) execute sale deed in favour of purchaser have it duly stamped and regd