Divorce on the grounds of adultery..

My wife is christian, love Marriage held in 2008 in church, she just came with 2 dresses and bus fare.. we got married and have 2 kids aged 6years girl, 2 yrs boy.. She torturing me from the next year of my marriage. in 2014 torture is very terrible. I got doubt and recorded her all phone call without her knowledge. i found she has extra martial relationship with another govt teacher. She is also a govt teacher. One day they went to lodge, that time she was pregnant. On the next day, they talking to each other.. how they participated in sex... how they enjoyed it... one question he asked her how much percentage of my features will come in next baby... she said i want your colour to the baby.. my husband is dark colour.. she says she is expecting your colour.. .. After i know this.. i asked her, she said i did nothing mistake.. so beat her with stick... she complained to the police that he is asking dowry, his parents and sisters harassing me.. for dowry. So police called me enquired. i showed all call recordings. They counselled and sent. I filed divorce petition in family court based on cruelty and adultery.. is it sufficient to prove... i have call history of both.. how many times they talk and sms each other. But i want content of sms they sent each other...is it possible to get evidence from lodge they spent... will court direct to concerned to collect all evidence.. shall i complain to the police...