Is it ok to recite any one of the kalma in salat just after we recite surah fatiha?
Whatever you recite in your prayer, has to be from the Quran.
So recite what is easy from it [Quran]
Also the Propher said:
When you stand for Prayer say Takbir and then recite from the Holy Qur'an (of what you know by heart)
If the kalima you are referring to is written in the Quran, then you can recite it after Sura Fatiha.
Just to let you know, it is enough to recite Sura Fatiha only in the prayer. You do not even need to recite anything else, as stated in the following hadith:
It was narrated that ‘Ata’ said: Abu Hurayrah said: In every prayer there is recitation. What we heard the Prophet (peace and blessings of Allaah be upon him) say, we tell you, and what he did not tell us about we cannot tell you. Whoever recites Umm al-Kitaab (i.e., Soorat al-Faatihah) has done enough, and whoever does more than that, that is better.
Narrated by al-Bukhaari, 738; Muslim, 396.
We should always try to do what is better, so we should try to recite a surah after Fatiha.
And Allah knows best.