How is my Tomato plant ?

Hi experts, this is my Roma variety tomato, it's 51 days old I transplanted it a week or two ago, it's not too small as it's looking in the picture because I buried it's stem quite deeper, I just want to know is it doing good or not and how to make it bigger, I love in south Asia so it gets sun for 6 hours of sunlight and temperature remains in range of 23-32 degree Celsius.