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I bought an iPhone 3GS running ios 4.1 (used). I bought the phone to run a specific ios app. That app required ios 5.1 or later. I upgraded to ios 6.1.3 from itunes software. (as itunes prompted me). After upgrading, i chose English language and country to India to setup. After that, I connected to wifi. I got error like "apple server is busy. try after sometimes....' I used itunes option too. I got error "SIM card is not inserted"

I want to solve this issue withouting downloading any big ipsw file. I have original ios 6.1.3 on my pc. Please help me solve jailbreak it. Unthered JB is preferred.