1. Jamat has its own internal supporters and businesses, and also has foreign supporters from the Arab world and Pakistan e.g. the Pakistani Jamat e Islami. I won't say who but it will be pretty obvious to anyone with sense but the organization also recieves support from the intelligence organization of one state which sees the Jamat as a valuable tool in what it sees as its turf war with India. Let's leave it at that.
2. The organizations support in Bangladesh is decreasing and will continue to decrease, and the main way to defeat them is education.
As anyone who really knows the true nature of this organization and its history will be repulsed and disgusted.
3. I do not think Jamat will be banned in Bangladesh.
The main reason is because the USA (which has far more influence than the way overexaggerated Indian influence) wants a fundamentalist "Islamic" party in Bangladesh as a source of leverage against India and part of its strategy of promoting radicals in the Muslim world in order for them to be problematic for America's rivals.
4. So to state again I do not think Jamat will ever be banned.
But in that extremely unlike scenario the Jamat would either do three things.
i: Join with the BNP (which for me would be a good outcome as the BNP is a nationalist organization and not a pro-Pakistani/Pakistanophilic organization like Jamat)
ii: Stand as independents
iii: Regroup under a different name.
Option iii is what Turkey's "Islamist" party, (the Refah, Fazilet, Saadet) has done after successive bans (same party, different name) but more importantly is the younger and more progressive elements of the Refah party went on to form a more moderate AKP, which is now the most successful party in Turkey's history.
If the Jamat were to reform itself and do some of the things suggested by Kalu_Miah (e.g. distancing itself from war criminals, end Pakistanophilia etc) then I could live with them. My greatest concern with them is their agenda to re-integrate Bangladesh with Pakistan, which they deny in public as a group but even some of their supporters say at times.
5. The Awami League are also another corrupt organization and worked and allied with the Jamat before as @Fallstaff has commendably stated so many times. This angered many independent non-partisan liberals in Bangladesh such as Jahanara Imam.
Jahanara Imam
For her efforts in bringing Jamati war criminals to account and opposition to the Awami-Jamat alliance, Jahanara Imam was insulted and attacked by the corrupt and power-hungry Hasina.
This also inconveniences the Jamati narrative and propaganda that the Awami League is an "evil stooge of India" which if it was, then why did the Jamatis ally with Indian "dalals"?
The fact is the Awami League though favourable towards India to an extent and recieving some Indian intelligence support (Jamat recieves the support of "another" foreign intelligence agency) is not an Indian-controlled organization or an Indian puppet.
The Awami League's war crimes and calls to ban Jamat stem less from sincere hatred of the group and its crimes against humanity but from a political agenda, so should not be taken too seriously.
To sum up, the Jamati threat to Bangladesh is not that major and the Awami League engages in Jamati-bashing to gain popularity. However the Jamat is definitely a threat to Bangladeshi national security and should ultimately be neutralized and the best way to do that is education and maintain the economic and socio-economic progress Bangladesh is making.
This forum - dominated by Jamatis (4.6% of the population) - should not be taken seriously.