How to behave in a group in college?

Well im a student of a sixth form coll, i havent got a lot of friends,the main reason being i moved to the uk a yr ago from india.I find it particularly difficult to settle in a group..u know a group with whom u spend ure recess breaks or smethin....

Recently a girl came up to me and asked me to join her group beacuse i was sitting there alone. I obliged, it was alrite for the first 15-20 mins..there were 3 guys, a couple and the girl who had asked me to join the group..A majority of the talking was done wid the girl..u know the general stuff..like wat subjects u doin etc etc..Ten i told her that im Indian and i moved here a yr ago..she questioned me about different things related to india..like were im from in india etc... ten one of the guys puts up a question..''Do Indians have sex i asked him wether he was jokin or somethin..he didnt reply and i guessing I messed up here ...since i figured that he must have watched something related to Indians and their long tradtions of Kamsutra n all.. lol i know...i dint judge it that well, but he didnt reply and infact...it was like all akward for a couple of mins and then someone changed the topic.
My question here is ,whether i should go back to the group i met.?.or remain alone eating ma luch all by myself..im not desperate or such, i have been avoidng group situations merely for this reason ie UNEXPECTED BEHAVIOUR OR RANDOM QUESTIONS...im not really good at this...wat do i do? and to add to the dilemma this group of students are the lower sixth batch..i am an upersixth student...i dont know wat to do ...how to tackle such group situation in future..could u advice me on how u personally tackle such situations..i know wat im askin ...kindly try and be specific...if possible like an example...? u know wat i mean..neways thank u if u answer this it will put my mind to rest..i can move on and make new friends ten...join a group and have ma breaks in joy hehe...ahhh! that would just be perfect...neways plz help
Oh yes a bit of background im a bit shy..but im not scared at all...infact i feel at times that few peopleare quite apprehensive about appraoching me..im that kind of guy..non-intetionally and some times im like this as self defense habit..u know dont let ma guard down..well now u know basiclaly wat i am..so kindly advice me on the following''How to behave in a group in college.eg..a tricky question or situation'' thank you..

well if u ask me its always important to have friends. so i think it would be best in finding a group of friends. i think u should go back to ur old group of friends as they seem quite open to having u in their group. there will always be akward moments of conversation bu dont let that prevent u from making new friends. random questions and unexpected behaviour is always present among groups of friends so try and get used to it. just be random and spontaneous urself! that is what makes groups of friends fun. and having friends younger than u is perfectly alright. try just being urself and opening out to them alitttle. all the best in ur future endeavours.

Be yourself, have a good sense of humour an you will eventually find friends. If you're feeling forced to do it, it simply won't work out. Don't give a cr@p about what the others say do what you want